## toLower + [link](./toLower "Link to this entry.") + [source](https://github.com/lodash/lodash/blob/4.5.0正式版/lodash.src.js#L12773 "View in source.") + [npm](https://www.npmjs.com/package/lodash.tolower "See the npm package.") ``` _.toLower([string='']) ``` 转换整体的字符串为小写 ### 参数 1. [string=''] (string) 要转换的字符串 ### 返回值 (string) 返回小写的字符串 ### 示例 ``` _.toLower('--Foo-Bar'); // => '--foo-bar' _.toLower('fooBar'); // => 'foobar' _.toLower('__FOO_BAR__'); // => '__foo_bar__' ```