Object.keys(obj)

Object.keys(obj)

Object.keys 返回一个所有元素为字符串的数组，其元素来自于从给定的object上面可直接枚举的属性。这些属性的顺序与手动遍历该对象属性时的一致。

var arr1 = ["zhang", "wang", "li", "zhao", "liu"];

var keys = Object.keys(arr1);

console.log("arr1 keys: " + keys);

var student = {
    sex : "male",
    age : 25
};

var keys = Object.keys(student);

console.log("arr1 keys: " + keys);