小于等于（<=）
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.
小于等于运算符（<=）在左操作数小于等于右操作数时返回 true，否则返回 false。
尝试一下
console.log(5 <= 3); // Expected output: false console.log(3 <= 3); // Expected output: true // Compare bigint to number console.log(3n <= 5); // Expected output: true console.log("aa" <= "ab"); // Expected output: true 语法
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x <= y 描述
操作数比较使用与小于运算符相同的算法，除了相等的值（在尝试转换后）会返回 true。
示例
字符串与字符串比较
js
console.log("a" <= "b"); // true console.log("a" <= "a"); // true console.log("a" <= "3"); // false 字符串与数值比较
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console.log("5" <= 3); // false console.log("3" <= 3); // true console.log("3" <= 5); // true console.log("hello" <= 5); // false console.log(5 <= "hello"); // false 数值与数值比较
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console.log(5 <= 3); // false console.log(3 <= 3); // true console.log(3 <= 5); // true 数值与大整型比较
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console.log(5n <= 3); // false console.log(3 <= 3n); // true console.log(3 <= 5n); // true 比较 Boolean、null、undefined 和 NaN
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console.log(true <= false); // false console.log(true <= true); // true console.log(false <= true); // true console.log(true <= 0); // false console.log(true <= 1); // true console.log(null <= 0); // true console.log(1 <= null); // false console.log(undefined <= 3); // false console.log(3 <= undefined); // false console.log(3 <= NaN); // false console.log(NaN <= 3); // false 规范
| Specification |
|---|
| ECMAScript® 2026 Language Specification # sec-relational-operators |
