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

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参见