[JavaScript知识库]javascript判断是否是空对象以及对象的遍历

// 判断对象是否为空对象
// 1.for...in循环
const obj = {};
const objIsEmpty1 = (obj) => {
    for (let key in obj) {
        return false;
    }
    return true;
};
//2.json.parse
const objIsEmpty2 = (obj) => {
    if (JSON.stringify(obj) === '{}') {
        return true;
    }
    return false;
};
//3.Object.keys
const objIsEmpty3 = (obj) => {
    const key = Object.keys(obj);
    if (key.length === 0) {
        return true;
    }
    return false;
};
//4.Object.getOwnPropertyNames
const objIsEmpty4 = (obj) => {
    const key = Object.getOwnPropertyNames(
    if (key.length === 0) {
        return true;
    }
    return false;
};
console.log(objIsEmpty1(obj));
console.log(objIsEmpty2(obj));
console.log(objIsEmpty3(obj));
console.log(objIsEmpty4(obj));