合约逻辑

控制流

• if(statement){}else{}
• for(statement){}
  • for 循环长度不定的元素时，一定要控制范围，防止 out-of-gas
• while(statement){}
  • while 循环执行直到不满足条件，同样在 statement 中要控制循环范围
• do{}while(statement)
  • 先执行逻辑，在执行判断
  • 执行直到不满足条件，同样在 statement 中要控制循环范围
• 循环过程关键字
  • continue：跳出当前循环，立即进入下一个循环
  • break：终止当前循环
• try()catch{}
  • 异常捕获
• 三元操作符
  • a>b?a:b

// SPDX-License-Identifier: MIT
pragma solidity 0.8.26;

contract Logic {
  bool ifFlag = true;
  uint32[] raffleIds;
  uint256 executeNumber;

  function IfLogic() external view returns (bool) {
    if (ifFlag) {
      return (true);
    } else {
      return (false);
    }
  }

  function quicksort(uint256[] memory a)
  public
  pure
  returns (uint256[] memory)
  {
    uint256 len = a.length;
    for (uint256 i = 1; i < len; i++) {
      uint256 key = a[i];
      uint256 j = i;
      while (j >= 1 && key < a[j - 1]) {
        a[j] = a[j - 1];
        j--;
      }
      a[j] = key;
    }
    return a;
  }

  // Don't write loops that are unbounded as this can hit the gas limit, causing your transaction to fail.
  function forExecuteRaffle(uint256 count) external {
    uint256 length = raffleIds.length;
    uint256 ncount = executeNumber + count >= length
      ? length
      : executeNumber + count;
    uint256 temp = executeNumber;
    executeNumber = ncount;
    for (uint256 i = temp; i < ncount; i++) {
      // do something
    }
  }

  // Don't write loops that are unbounded as this can hit the gas limit, causing your transaction to fail.
  function whileExecuteRaffle(uint256 count) external {
    uint256 length = raffleIds.length;
    uint256 ncount = executeNumber + count >= length
      ? length
      : executeNumber + count;
    uint256 temp = executeNumber;
    executeNumber = ncount;
    while (temp < ncount) {
      // do something
    }
  }

  // do something first, then do statement check.
  function dowhileCheck(uint256 _number) public pure returns (uint256) {
    do {
      _number += 1;
    } while (_number < 15);
    return _number; //_number+1
  }
}