比较运算符

在以太坊虚拟机（EVM）中，选择比较运算符会影响智能合约的效率和燃气消耗。 Opting for < (less than) and > (greater than) over ≤ (less than or equal to) and ≥ (greater than or equal to) is notably more gas-efficient. 这是因为 EVM 的设计中没有直接的操作码指令支持 ≤ 和 ≥，实现这些比较需要额外的操作。

Given that iszero consumes 3 units of gas, utilizing ≤ and ≥ in contracts that frequently perform comparisons can lead to increased gas expenditures.

代码演示

contract CompareLessThan {
    // gas: 247
    function isSmallerThan(uint256 value) external pure returns (bool) {
        return value < 8;
    }
}

contract CompareLessThanOrEqual {
    // gas: 250
    function isSmallerThanOrEqual(uint256 value) external pure returns (bool) {
        return value <= 7;
    }
}

假设 value 值为7，两个函数将返回相同的结果。 However, the < operator will be more gas-efficient than the <= operator.

关于 gas 优化的建议：

🌟 Using the < and > operators is more gas-efficient than <= and >= in smart contracts.