String.prototype.toLowerCase()

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

StringtoLowerCase() 方法将该字符串转换为小写形式。

尝试一下

const sentence = "The quick brown fox jumps over the lazy dog.";

console.log(sentence.toLowerCase());
// Expected output: "the quick brown fox jumps over the lazy dog."

语法

js
toLowerCase()

返回值

一个新的字符串,表示转换为小写的调用字符串。

描述

toLowerCase() 方法返回将字符串转换为小写形式后的值。toLowerCase() 不会影响字符串 str 本身的值。

示例

使用 toLowerCase()

js
console.log("ALPHABET".toLowerCase()); // 'alphabet'

规范

Specification
ECMAScript® 2025 Language Specification
# sec-string.prototype.tolowercase

浏览器兼容性

Report problems with this compatibility data on GitHub
desktopmobileserver
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
Deno
Node.js
toLowerCase

Legend

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Full support
Full support

参见