js正则表达式 匹配汉字

const regex = /[\u4e00-\u9fa5]+/;

function isAllChinese(str) {
    const regex = /^[\u4e00-\u9fa5]+$/;
    return regex.test(str);
}

console.log(isAllChinese("你好")); // true
console.log(isAllChinese("hello")); // false
console.log(isAllChinese("你好hello")); // false

function extractChinese(str) {
    const regex = /[\u4e00-\u9fa5]+/g;
    return str.match(regex);
}

console.log(extractChinese("hello你好world")); // ["你好"]
console.log(extractChinese("JavaScript编程")); // ["JavaScript", "编程"]

function replaceNonChinese(str) {
    const regex = /[^[\u4e00-\u9fa5]]+/g;
    return str.replace(regex, '');
}

console.log(replaceNonChinese("hello你好world")); // "你好"
console.log(replaceNonChinese("JavaScript编程123")); // "编程"