pragma solidity ^0.4.18; contract StringToLower { function _toLower(string str) returns (string) { bytes memory bStr = bytes(str); bytes memory bLower = new bytes(bStr.length); for (uint i = 0; i < bStr.length; i++) { // Uppercase character... if ((bStr[i] >= 65) && (bStr[i] <= 90)) { // So we add 32 to make it lowercase bLower[i] = bytes1(int(bStr[i]) + 32); } else { bLower[i] = bStr[i]; } } return string(bLower); } }