Solidity - 比較運算子

示例

以下程式碼展示瞭如何在 Solidity 中使用比較運算子。

pragma solidity ^0.5.0;

contract SolidityTest {
   uint storedData; 
   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(result); 
   }
   function integerToString(uint _i) internal pure 
      returns (string memory _uintAsString) {
      
      if (_i == 0) {   //comparison operator
         return "0";
      }
      uint j = _i;
      uint len;
      
      while (j != 0) {  //comparison 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);//access local variable
   }
}

按照 Solidity 第一個應用程式 章節中提供的步驟執行上述程式。

輸出

0: string: 3