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.
String 的 toLowerCase() 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® 2026 Language Specification # sec-string.prototype.tolowercase |