从对象中获取数组数据

Question

我在一个对象中有一个数组，如下所示：

[
{ "id": 244, "title": "myBook.pdf", "author": "Kevin"},
{ "id": 370, "title": "Bookpress.pdf", "author": "Justin"},
{ "id": 433, "title": "Uptown.pdf", "author": "David"},
]

如何获取所有标题数据的所有数据？所需资料为： myBook.pdf、Bookpress.pdf、Uptown.pdf

Answer 1

如果你使用 lodash，你可以简单地这样做

var data = [
  { "id": 244, "title": "myBook.pdf", "author": "Kevin"},
  { "id": 370, "title": "Bookpress.pdf", "author": "Justin"},
  { "id": 433, "title": "Uptown.pdf", "author": "David"},
]

var result = _(data).map("title").value();

给你

result
(3) ["myBook.pdf", "Bookpress.pdf", "Uptown.pdf"]

但是由于这听起来像是一个作业问题，所以您应该尝试在没有库的情况下自己完成。

Answer 2

只需使用Array#map函数。使用join(',')函数来应用逗号

var arr = [
{ "id": 244, "title": "myBook.pdf", "author": "Kevin"},
{ "id": 370, "title": "Bookpress.pdf", "author": "Justin"},
{ "id": 433, "title": "Uptown.pdf", "author": "David"},
]

console.log(arr.map(a=> a.title))
console.log(arr.map(a=> a.title).join(','))

Answer 3

使用 for 循环遍历数组并使用 javascript 对象表示法获取所需的对象属性并将其附加到 html 或以您喜欢的任何方式使用。

var arr =[
{ "id": 244, "title": "myBook.pdf", "author": "Kevin"},
{ "id": 370, "title": "Bookpress.pdf", "author": "Justin"},
{ "id": 433, "title": "Uptown.pdf", "author": "David"},
]

for (var i =0;i < arr.length;i++){

var el = document.getElementById("demo");
el.innerHTML += arr[i].title
}

<div id="demo">
</div>