Solidity - 逻辑运算符

示例

尝试以下代码来了解如何在 Solidity 中实现逻辑运算符。

pragma solidity ^0.5.0;

contract SolidityTest {
   uint storedData; // State variable
   constructor() public{
      storedData = 10;   
   }
   function getResult() public view returns(string memory){
      uint a = 1; // local variable
      uint b = 2;
      uint result = a + b;
      return integerToString(storedData); //access the state variable
   }
   function integerToString(uint _i) internal pure 
      returns (string memory) {
      
      if (_i == 0) {
         return "0";
      }
      uint j = _i;
      uint len;
      
      while (!(j == 0)) {  //logical operator
         len++;
         j /= 10;
      }
      bytes memory bstr = new bytes(len);
      uint k = len - 1;
      
      while (_i != 0) {
         bstr[k--] = byte(uint8(48 + _i % 10));
         _i /= 10;
      }
      return string(bstr);
   }
}

使用 Solidity First 应用 章节中提供的步骤运行上述程序。

输出

0: string: 3

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