meterify.utils

This package provides utility functions for dapps and other packages.
randomHex
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    meterify.utils.randomHex(size)
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The randomHex library to generate cryptographically strong pseudo-random HEX strings from a given byte size.
Example:
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​
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    meterify.utils.randomHex(32)
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    > "0xa5b9d60f32436310afebcfda832817a68921beb782fabf7915cc0460b443116a"
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​
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    meterify.utils.randomHex(4)
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    > "0x6892ffc6"
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​
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    meterify.utils.randomHex(2)
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    > "0x99d6"
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​
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    meterify.utils.randomHex(1)
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    > "0x9a"
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​
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    meterify.utils.randomHex(0)
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    > "0x"
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Parameters:
1.
size - Number: The byte size for the HEX string, e.g. 32 will result in a 32 bytes HEX string with 64 characters preficed with "0x".
Returns:
String: The generated random HEX string.
BN    
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meterify.utils.BN(mixed)
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The BN.js library for calculating with big numbers in JavaScript. See the BN.js documentation for details.
Example:
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​
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    const BN = meterify.utils.BN;
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​
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    new BN(1234).toString();
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    > "1234"
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​
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    new BN('1234').add(new BN('1')).toString();
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    > "1235"
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​
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    new BN('0xea').toString();
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    > "234"
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Note: For safe conversion of many types, including BigNumber.js, use utils.toBN.
Parameters:
1.
value - String|Number: A number, number string or HEX string to convert to a BN object.
Returns:
Object: The BN.js_ instance.
isBN
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​
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    meterify.utils.isBN(bn)
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Checks if a given value is a BN.js instance.
Example:
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​
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    const number = new BN(10);
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​
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    meterify.utils.isBN(number);
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    > true
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Parameters:
1.
bn - Object: An BN.js instance.
Returns:
Boolean
isBigNumber
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    meterify.utils.isBigNumber(bignumber)
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Checks if a given value is a BigNumber.js instance.
Example:
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​
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    const number = new BigNumber(10);
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​
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    meterify.utils.isBigNumber(number);
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    > true
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Parameters:
1.
BigNumber - Object: A BigNumber.js instance.
Returns:
Boolean
keccak256
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​
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    meterify.utils.keccak256(string)
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    meterify.utils.sha3(string) // ALIAS
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Will calculate the keccak256 of the input.
Example:
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    meterify.utils.keccak256('234'); // taken as string
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    > "0xc1912fee45d61c87cc5ea59dae311904cd86b84fee17cc96966216f811ce6a79"
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​
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    meterify.utils.keccak256(new BN('234'));
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    > "0xbc36789e7a1e281436464229828f817d6612f7b477d66591ff96a9e064bcc98a"
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​
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    meterify.utils.keccak256(234);
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    > null // can't calculate the hash of a number
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​
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    meterify.utils.keccak256(0xea); // same as above, just the HEX representation of the number
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    > null
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​
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    meterify.utils.keccak256('0xea'); // will be converted to a byte array first, and then hashed
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    > "0x2f20677459120677484f7104c76deb6846a2c071f9b3152c103bb12cd54d1a4a"
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Note: To mimic the keccak256 behavior of Solidity, use soliditySha3.
Parameters:
1.
string - String: A string to hash.
Returns:
String: the result hash.
soliditySha3    
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meterify.utils.soliditySha3(param1 [, param2, ...])
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Will calculate the sha3 of given input parameters in the same way solidity would. This means arguments will be ABI converted and tightly packed before being hashed.
Example:
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meterify.utils.soliditySha3('234564535', '0xfff23243', true, -10);
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    // auto detects:        uint256,      bytes,     bool,   int256
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    > "0x3e27a893dc40ef8a7f0841d96639de2f58a132be5ae466d40087a2cfa83b7179"
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​
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    meterify.utils.soliditySha3('Hello!%'); // auto detects: string
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    > "0x661136a4267dba9ccdf6bfddb7c00e714de936674c4bdb065a531cf1cb15c7fc"
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​
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    meterify.utils.soliditySha3('234'); // auto detects: uint256
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    > "0x61c831beab28d67d1bb40b5ae1a11e2757fa842f031a2d0bc94a7867bc5d26c2"
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​
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    meterify.utils.soliditySha3(0xea); // same as above
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    > "0x61c831beab28d67d1bb40b5ae1a11e2757fa842f031a2d0bc94a7867bc5d26c2"
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​
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    meterify.utils.soliditySha3(new BN('234')); // same as above
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    > "0x61c831beab28d67d1bb40b5ae1a11e2757fa842f031a2d0bc94a7867bc5d26c2"
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​
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    meterify.utils.soliditySha3({type: 'uint256', value: '234'})); // same as above
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    > "0x61c831beab28d67d1bb40b5ae1a11e2757fa842f031a2d0bc94a7867bc5d26c2"
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​
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    meterify.utils.soliditySha3({t: 'uint', v: new BN('234')})); // same as above
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    > "0x61c831beab28d67d1bb40b5ae1a11e2757fa842f031a2d0bc94a7867bc5d26c2"
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​
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    meterify.utils.soliditySha3('0x407D73d8a49eeb85D32Cf465507dd71d507100c1');
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    > "0x4e8ebbefa452077428f93c9520d3edd60594ff452a29ac7d2ccc11d47f3ab95b"
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​
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    meterify.utils.soliditySha3({t: 'bytes', v: '0x407D73d8a49eeb85D32Cf465507dd71d507100c1'});
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    > "0x4e8ebbefa452077428f93c9520d3edd60594ff452a29ac7d2ccc11d47f3ab95b" // same result as above
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​
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    meterify.utils.soliditySha3({t: 'address', v: '0x407D73d8a49eeb85D32Cf465507dd71d507100c1'});
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    > "0x4e8ebbefa452077428f93c9520d3edd60594ff452a29ac7d2ccc11d47f3ab95b" // same as above, but will do a checksum check, if its multi case
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​
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    meterify.utils.soliditySha3({t: 'bytes32', v: '0x407D73d8a49eeb85D32Cf465507dd71d507100c1'});
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    > "0x3c69a194aaf415ba5d6afca734660d0a3d45acdc05d54cd1ca89a8988e7625b4" // different result as above
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​
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    meterify.utils.soliditySha3({t: 'string', v: 'Hello!%'}, {t: 'int8', v:-23}, {t: 'address', v: '0x85F43D8a49eeB85d32Cf465507DD71d507100C1d'});
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    > "0xa13b31627c1ed7aaded5aecec71baf02fe123797fffd45e662eac8e06fbe4955"
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Parameters:
1.
paramX - Mixed: Any type, or an object with {type: 'uint', value: '123456'} or {t: 'bytes', v: '0xfff456'}. Basic types are autodetected as follows:
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String non numerical UTF-8 string is interpreted as string.
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String|Number|BN|HEX positive number is interpreted as uint256.
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String|Number|BN negative number is interpreted as int256. 
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Boolean as bool. 
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String HEX string with leading 0x is interpreted as bytes. 
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HEX HEX number representation is interpreted as uint256.
Returns:
String: the result hash.
isHex    
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meterify.utils.isHex(hex)
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Checks if a given string is a HEX string.
Example:
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    meterify.utils.isHex('0xc1912');
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    > true
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​
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    meterify.utils.isHex(0xc1912);
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    > true
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​
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    meterify.utils.isHex('c1912');
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    > true
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​
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    meterify.utils.isHex(345);
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    > true // this is tricky, as 345 can be a a HEX representation or a number, be careful when not having a 0x in front!
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​
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    meterify.utils.isHex('0xZ1912');
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    > false
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​
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    meterify.utils.isHex('Hello');
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    > false
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Parameters:
1.
hex - String|HEX: The given HEX string.
Returns:
Boolean
isHexStrict    
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meterify.utils.isHexStrict(hex)
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Checks if a given string is a HEX string. Difference to meterify.utils.isHex() is that it expects HEX to be prefixed with 0x.
Example:
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    meterify.utils.isHexStrict('0xc1912');
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    > true
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​
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    meterify.utils.isHexStrict(0xc1912);
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    > false
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​
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    meterify.utils.isHexStrict('c1912');
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    > false
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​
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    meterify.utils.isHexStrict(345);
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    > false // this is tricky, as 345 can be a a HEX representation or a number, be careful when not having a 0x in front!
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​
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    meterify.utils.isHexStrict('0xZ1912');
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    > false
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​
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    meterify.utils.isHex('Hello');
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    > false
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Parameters:
1.
hex - String|HEX: The given HEX string.
Returns:
Boolean
isAddress    
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meterify.utils.isAddress(address,  [, chainId])
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Checks if a given string is a valid Meter address. It will also check the checksum, if the address has upper and lowercase letters.
Example:
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    meterify.utils.isAddress('0xc1912fee45d61c87cc5ea59dae31190fffff232d');
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    > true
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​
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    meterify.utils.isAddress('c1912fee45d61c87cc5ea59dae31190fffff232d');
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    > true
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​
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    meterify.utils.isAddress('0XC1912FEE45D61C87CC5EA59DAE31190FFFFF232D');
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    > true // as all is uppercase, no checksum will be checked
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​
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    meterify.utils.isAddress('0xc1912fEE45d61C87Cc5EA59DaE31190FFFFf232d');
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    > true
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​
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    meterify.utils.isAddress('0xC1912fEE45d61C87Cc5EA59DaE31190FFFFf232d');
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    > false // wrong checksum
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​
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    meterify.utils.isAddress('0x5aaEB6053f3e94c9b9a09f33669435E7ef1bEAeD', 30);
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    > true
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Parameters:
1.
address - String: An address string.
2.
chainId - number (optional): Chain id where checksummed address should be valid, defaults to null. RSKIP-60 for details.
Returns:
Boolean
toChecksumAddress
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    meterify.utils.toChecksumAddress(address[, chainId])
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Will convert an upper or lowercase Meter address to a checksum address.
Example:
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​
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    meterify.utils.toChecksumAddress('0xc1912fee45d61c87cc5ea59dae31190fffff232d');
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    > "0xc1912fEE45d61C87Cc5EA59DaE31190FFFFf232d"
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​
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    meterify.utils.toChecksumAddress('0XC1912FEE45D61C87CC5EA59DAE31190FFFFF232D');
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    > "0xc1912fEE45d61C87Cc5EA59DaE31190FFFFf232d" // same as above
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​
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    meterify.utils.toChecksumAddress('0x5aaeb6053f3e94c9b9a09f33669435e7ef1beaed', 30);
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    > "0x5aaEB6053f3e94c9b9a09f33669435E7ef1bEAeD"
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Parameters:
1.
address - String: An address string.
2.
chainId - number (optional): Chain id where checksummed address should be valid, defaults to null. RSKIP-60 for details.
Returns:
String: The checksum address.
stripHexPrefix
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     meterify.utils.stripHexPrefix(address)
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Removes the prefix 0x from a given hex if it exists.
Example:
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      meterify.utils.stripHexPrefix('0xc1912fEE45d61C87Cc5EA59DaE31190FFFFf232d');
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     > "c1912fEE45d61C87Cc5EA59DaE31190FFFFf232d"
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Parameters:
1.
hex - String: Hex
Returns:
String: Hex without prefix.
checkAddressChecksum
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​
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    meterify.utils.checkAddressChecksum(address [, chainId])
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Checks the checksum of a given address. Will also return false on non-checksum addresses.
Example:
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    meterify.utils.checkAddressChecksum('0xc1912fEE45d61C87Cc5EA59DaE31190FFFFf232d');
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    > true
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​
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    meterify.utils.checkAddressChecksum('0x5aAeb6053F3e94c9b9A09F33669435E7EF1BEaEd', 31);
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    > true
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Parameters:
1.
address - String: An address string.
2.
chainId - number (optional): Chain id where checksummed address should be valid, defaults to null. RSKIP-60 for details.
Returns:
Boolean: true when the checksum of the address is valid, false if its not a checksum address, or the checksum is invalid.
toHex
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​
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    meterify.utils.toHex(mixed)
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Will auto convert any given value to HEX. Number strings will interpreted as numbers. Text strings will be interpreted as UTF-8 strings.
Example:
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    meterify.utils.toHex('234');
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    > "0xea"
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​
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    meterify.utils.toHex(234);
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    > "0xea"
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​
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    meterify.utils.toHex(new BN('234'));
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    > "0xea"
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​
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    meterify.utils.toHex(new BigNumber('234'));
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    > "0xea"
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​
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    meterify.utils.toHex('I have 100€');
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    > "0x49206861766520313030e282ac"
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Parameters:
1.
value - String|Number|BN|BigNumber: The input to convert to HEX.
Returns:
String: The resulting HEX string.
toBN    
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meterify.utils.toBN(number)
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Will safely convert any given value (including BigNumber.js instances) into a BN.js instance, for handling big numbers in JavaScript.
Example:
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    meterify.utils.toBN(1234).toString();
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    > "1234"
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​
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    meterify.utils.toBN('1234').add(meterify.utils.toBN('1')).toString();
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    > "1235"
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​
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    meterify.utils.toBN('0xea').toString();
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    > "234"
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Note: For just the BN.js class use utils.BN.
Parameters:
1.
number - String|Number|HEX: Number to convert to a big number.
Returns:
Object: The BN.js instance.
hexToNumberString
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    meterify.utils.hexToNumberString(hex)
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Returns the number representation of a given HEX value as a string.
Example:
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    meterify.utils.hexToNumberString('0xea');
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    > "234"
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Parameters:
1.
hexString - String|HEX: A string to hash.
Returns:
String: The number as a string.
hexToNumber
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​
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    meterify.utils.hexToNumber(hex)
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    meterify.utils.toDecimal(hex) // ALIAS, deprecated
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Returns the number representation of a given HEX value.
Example:
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    meterify.utils.hexToNumber('0xea');
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    > 234
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Note: This is not useful for big numbers, use utils.toBN instead.
Parameters:
1.
hexString - String|HEX: A string to hash.
Returns:
Number
numberToHex
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​
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    meterify.utils.numberToHex(number)
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    meterify.utils.fromDecimal(number) // ALIAS, deprecated
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Returns the HEX representation of a given number value.
Example:
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    meterify.utils.numberToHex('234');
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    > '0xea'
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Parameters:
1.
number - String|Number|BN|BigNumber: A number as string or number.
Returns:
String: The HEX value of the given number.
hexToUtf8
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​
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    meterify.utils.hexToUtf8(hex)
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    meterify.utils.hexToString(hex) // ALIAS
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    meterify.utils.toUtf8(hex) // ALIAS, deprecated
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Returns the UTF-8 string representation of a given HEX value.
Example:
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    meterify.utils.hexToUtf8('0x49206861766520313030e282ac');
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    > "I have 100€"
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Parameters:
1.
hex - String: A HEX string to convert to a UTF-8 string.
Returns:
String: The UTF-8 string.
hexToAscii
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​
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    meterify.utils.hexToAscii(hex)
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    meterify.utils.toAscii(hex) // ALIAS, deprecated
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Returns the ASCII string representation of a given HEX value.
Example:
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    meterify.utils.hexToAscii('0x4920686176652031303021');
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    > "I have 100!"
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Parameters:
1.
hex - String: A HEX string to convert to a ASCII string.
Returns:
String: The ASCII string.
utf8ToHex    
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    meterify.utils.utf8ToHex(string)
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    meterify.utils.stringToHex(string) // ALIAS
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    meterify.utils.fromUtf8(string) // ALIAS, deprecated
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Returns the HEX representation of a given UTF-8 string.
Example:
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    meterify.utils.utf8ToHex('I have 100€');
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    > "0x49206861766520313030e282ac"
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Parameters:
1.
string - String: A UTF-8 string to convert to a HEX string.
Returns:
String: The HEX string.
asciiToHex   
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    meterify.utils.asciiToHex(string)
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    meterify.utils.fromAscii(string) // ALIAS, deprecated
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Returns the HEX representation of a given ASCII string. If you would like to transform an ASCII string into a valid bytes4, bytes8 etc. value then please pass the correct length as the second parameter.
Example:
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    meterify.utils.asciiToHex('I have 100!');
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    > "0x4920686176652031303021000000000000000000000000000000000000000000"
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​
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    // transforming to a bytes4 value:
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    meterify.utils.asciiToHex('yes', 4);
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​
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    // transforming to a bytes8 value:
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    meterify.utils.asciiToHex('yes', 8);
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​
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    //etc.
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Parameters:
1.
string - String: A ASCII string to convert to a HEX string.
2.
length - Number: The length of the returned hex string. The default size is 32 e.g.: bytes32.
Returns:
String: The HEX string.
hexToBytes    
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meterify.utils.hexToBytes(hex)
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Returns a byte array from the given HEX string.
Example:
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    meterify.utils.hexToBytes('0x000000ea');
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    > [ 0, 0, 0, 234 ]
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​
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    meterify.utils.hexToBytes(0x000000ea);
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    > [ 234 ]
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Parameters:
hex - String|HEX: A HEX to convert.
Returns:
Array: The byte array.
bytesToHex
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meterify.utils.bytesToHex(byteArray)
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Returns a HEX string from a byte array.
Example:
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    meterify.utils.bytesToHex([ 72, 101, 108, 108, 111, 33, 36 ]);
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    > "0x48656c6c6f2125"
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Parameters:
byteArray - Array: A byte array to convert.
Returns:
String: The HEX string.
toWei    
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meterify.utils.toWei(number [, unit])
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Converts a Meter value into wei.
Example:
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    meterify.utils.toWei('1', 'ether');
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    > "1000000000000000000"
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​
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    meterify.utils.toWei('1', 'finney');
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    > "1000000000000000"
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​
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    meterify.utils.toWei('1', 'szabo');
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    > "1000000000000"
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​
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    meterify.utils.toWei('1', 'shannon');
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    > "1000000000"
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Note: wei are the smallest conversion unit, and you should always make calculations in wei and convert only for display reasons.
Parameters:
1.
number - String|BN: The value.
2.
unit - String (optional, defaults to "ether"): The ether to convert from. Possible units are:
1.
noether: '0'
2.
wei: '1'
3.
kwei: '1000'
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Kwei: '1000'
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babbage: '1000'
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femtoether: '1000'
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mwei: '1000000'
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Mwei: '1000000'
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lovelace: '1000000'
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picoether: '1000000'
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gwei: '1000000000'
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Gwei: '1000000000'
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shannon: '1000000000'
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nanoether: '1000000000'
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nano: '1000000000'
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szabo: '1000000000000'
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microether: '1000000000000'
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micro: '1000000000000'
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finney: '1000000000000000'
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milliether: '1000000000000000'
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milli: '1000000000000000'
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ether: '1000000000000000000'
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kether: '1000000000000000000000'
24.
grand: '1000000000000000000000'
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mether: '1000000000000000000000000'
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gether: '1000000000000000000000000000'
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tether: '1000000000000000000000000000000'
Returns:
String|BN: If a string is given it returns a number string, otherwise a BN.js instance.
fromWei
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    meterify.utils.fromWei(number [, unit])
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Converts any wei value into another value.
Example:
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    meterify.utils.fromWei('1', 'ether');
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    > "0.000000000000000001"
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​
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    meterify.utils.fromWei('1', 'finney');
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    > "0.000000000000001"
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​
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    meterify.utils.fromWei('1', 'szabo');
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    > "0.000000000001"
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​
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    meterify.utils.fromWei('1', 'shannon');
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    > "0.000000001"
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Note: wei are the smallest conversion unit, and you should always make calculations in wei and convert only for display reasons.
Parameters:
1.
number - String|BN: The value in wei.
2.
unit - String (optional, defaults to "ether"): The ether to convert to. Possible units are:
noether: '0'
wei: '1'
kwei: '1000'
Kwei: '1000'
babbage: '1000'
femtoether: '1000'
mwei: '1000000'
Mwei: '1000000'
lovelace: '1000000'
picoether: '1000000'
gwei: '1000000000'
Gwei: '1000000000'
shannon: '1000000000'
nanoether: '1000000000'
nano: '1000000000'
szabo: '1000000000000'
microether: '1000000000000'
micro: '1000000000000'
finney: '1000000000000000'
milliether: '1000000000000000'
milli: '1000000000000000'
ether: '1000000000000000000'
kether: '1000000000000000000000'
grand: '1000000000000000000000'
mether: '1000000000000000000000000'
gether: '1000000000000000000000000000'
tether: '1000000000000000000000000000000'
Returns:
String: It always returns a string number.
unitMap
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​
2
    meterify.utils.unitMap
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Shows all possible values and their amount in wei.
Example:
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​
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    meterify.utils.unitMap
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