Solidity while 循环

 

1. 语法

Solidity 中， while循环的语法如下：

while (表达式) {
   // 如果表达式的结果为真，就循环执行以下语句
   ......
}

 

2. 示例

// SPDX-License-Identifier: SimPL-3.0
pragma solidity ^0.7.0;
contract SolidityTest {
   uint storedData; 
   
   constructor() {
      storedData = 10;   
   }
   
   function getResult() public pure returns(string memory){
      uint a = 10; 
      uint b = 2;
      uint result = a + b;
      return integerToString(result); 
   }
   
   function integerToString(uint _i) internal pure 
      returns (string memory) {

      if (_i == 0) {
         return "0";
      }
      uint j = _i;
      uint len;

      while (j != 0) {
         len++;
         j /= 10;
      }
      bytes memory bstr = new bytes(len);
      uint k = len - 1;

      while (_i != 0) { // while 循环
         bstr[k--] = byte(uint8(48 + _i % 10));
         _i /= 10;
      }
      return string(bstr);
   }
}

运行上述程序，输出结果：

0: string: 12

Solidity do…while 循环： 1. 语法Solidity 中， do…while循环的语法如下：do { // 如果表达式的结果为真，就循环执行以下语句 ......} while (表达 ...