# solidity的函数修饰符

**Published by:** [leishen](https://paragraph.com/@ldplxp/)
**Published on:** 2022-05-17
**URL:** https://paragraph.com/@ldplxp/solidity

## Content

修饰符是可以在一个函数调用之前或之后运行的代码。 有三种形式：基础修饰符，带参数，夹在中间的(sandwich) 修饰符可以用来： 限制访问 验证输入 防止重入黑客攻击 contract FunctionModifier{ bool public paused; uint public count; modifier whenNotPaused(){ require(!paused, "the contract is paused"); // _;的意思是返回主函数 _; } modifier cap(uint _x){ require(_x < 100, "X >= 100"); _; } modifier sandwich(){ count += 10; _; count *= 2; } // 函数修饰符可以用一大堆 function incBy(uint _x) external whenNotPaused cap(_x) sandwich{ count += _x; } }

## Publication Information

- [leishen](https://paragraph.com/@ldplxp/): Publication homepage
- [All Posts](https://paragraph.com/@ldplxp/): More posts from this publication
- [RSS Feed](https://api.paragraph.com/blogs/rss/@ldplxp): Subscribe to updates
- [Twitter](https://twitter.com/binbinlee4): Follow on Twitter