我需要知道我在这里做错了什么

Question

{    "messages": [{        "msgFrom": "13223821242",        "msgBody": "Hi there"    }, {        "msgFrom": "Bill",        "msgBody": "Hello!"    }]}var loop = () => {  var arr = []  for (var i = 0 ; i<messages.length; i ++) {    arr.push(messages[1])  }  return loop()  console.log(arr)}我需要遍历这个对象并只获取推送到新数组中的消息相同的

Answer 1

arr.push(messages[1])

1 应该是 i，你每次都抓取相同的索引

Answer 2

有多个问题

假设对象有一个变量 obj

var loop = () => {

  var arr = []

  for (var i = 0 ; i< obj.messages.length; i ++) { //messages is a key of an object, so messages is undefined, it should be obj.messages.

    arr.push(messages[i]) //wrong index, you should push `i` and not 1

  }

  return arr; // loop() is a function, causing endless recursion, causing stack overflow!

  console.log(arr) // will never print since function already returns!; move before return if you want it to print

}

Answer 3

你可以使用解构，它简短而简单。

var obj = { "messages": [

        {

            "msgFrom": "13223821242",

            "msgBody": "Hi there"

        }, {

            "msgFrom": "Bill",

            "msgBody": "Hello!"

        }

    ]

};

var arr = [...obj.messages];

console.log(arr);