法1、

function getObjKeys() {    var obj = {
        "name": "zhangsan",
        "age": 30
    };
    let keys = Object.keys(obj);
    console.log(keys);
}

法2、

function getObjKeysByfor() {
    var keys = [];
    var obj = {
        "name": "zhangsan",
        "age": 30
    };
    for (let key in obj) {
        keys.push(key)
    }
    console.log(keys);
}

摘自：https://blog.csdn.net/xinusuoshu/article/details/63683706