遍历对象数组-TypeError:无法读取未定义的属性“名称" [英] Looping through array of objects - TypeError: Cannot read property 'name' of undefined

问题描述

我正在尝试从下面显示的 artists 数组(例如"Taylor Swift，蕾哈娜，贾斯汀·汀布莱克")中创建艺术家姓名的字符串，但 artist_obj 是未定义的，并且出现错误"TypeError:无法读取未定义的属性'名称'".我该如何解决?

I am trying to create a string of the artist's names from the artists array shown below (i.e. "Taylor Swift, Rihanna, Justin Timberlake"), but the artist_obj is undefined and I get the error "TypeError: Cannot read property 'name' of undefined". How do I fix this?

代码

 //Get info for each song
var artists = item["artists"],
artist = "";
var artists_count = 0;

 artists.forEach(function(item) {
      var artist_obj = item["artists_count"];
      if(artists_count !== 0) {
           artist = artist + ", " + artist_obj["name"];
      } else {
           artist += artist_obj["name"];
      }
      artists_count++;
 });

推荐答案

在您的代码中，您正在使用索引作为 item ["artists_count"] 来访问当前对象.因为"artists_count" 是字符串& ;，不会通过可变的价值！您必须使用 item [artists_count] 其中的双引号来传递变量！除此之外，您的代码还可以！

In your code you are accessing current object using index as item["artists_count"]. This wont work beacuase "artists_count" is a string & wont pass the varible value! You have to use item[artists_count] whichout double quotes to pass the variable! Apart from this you code is okay!

请注意，您传递给 forEach 的参数(即 item )是对当前对象的引用，因此无需保留单独的变量以维护&手动迭代索引.

And please note that the argument, (i.e. item) you are passing to the forEach is the reference to the current object, thus there is no need to keep a separate variable to maintain & manually iterate the index.

将您的代码更改为:

var artists = item["artists"],
artist = "";
var artists_count = 0; 

artists.forEach(function(item) {
      var artist_obj = item;
      if(artists_count !== 0) {
           artist = artist + ", " + artist_obj["name"];
      } else {
           artist += artist_obj["name"];
      }
      artists_count++;
 });

更干净的版本是:

var artists = item["artists"],
artist = "";
artists.forEach(function(item) {
     artist = artist + item["name"] + ", ";
});
artist = artist.replace(/,\s*$/, "");

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