在对象数组上迭代

Iterate over array of objects

本文关键字：迭代 数组 对象      更新时间：2024-05-12

我有一个类似的JSON字符串

 var json =  '{ "Comments": 
    [
      { "Id" : 1,"Comment" : "Test comment","Name" : "Yogesh","Child" : 0},
      { "Id" : 2,"Comment" : "Test comment II","Name" : "Yogesh","Child" : 0}
    ] 
    }';

我正在尝试对这些对象进行迭代，例如：

var parsedJSON = $.parseJSON(json);
var html = "";    
for (comment in parsedJSON.Comments) {
  html += "Id: " + comment.Id;
  html += "Comment: " + comment.Comment;
  html += "Name: " + comment.Name;
  html += "Child: " + comment.Child;
  html += "<br/>";
}

但在这里，for循环中的comment变成了0和1，我的意思不是一个对象，而是一个字符串，我如何在这个数组上迭代？

var json = '{ "Comments": [{ "Id" : 1,"Comment" : "Test comment","Name" : "Yogesh","Child" : 0},{ "Id" : 2,"Comment" : "Test comment II","Name" : "Yogesh","Child" : 0}] }';
var parsedJSON = $.parseJSON(json), // jsonData should json
    html = "",
    comments =parsedJSON.Comments; // keeping reference of parsedJSON and its an Array
// Here key will give 0, 1 etc ie. index of array
for (var key in comments) {
    html += "Id: " + comments[key].Id;
    html += "Comment: " + comments[key].Comment;
    html += "Name: " + comments[key].Name;
    html += "Child: " + comments[key].Child;
    html += "<br/>";
}

演示

您似乎误解了for..in循环的工作方式。CCD_ 5将迭代地成为该阵列的密钥。在任何情况下，都不应该在数组上使用for..in，而应该只在对象上使用——即使这样也要小心。

var l = parsedJSON.Comments.length, i, comment;
for( i=0; i<l; i++) {
    comment = parseJSON.Comments[i];
    // do stuff with comment
}

你可以试试这个：

     var JsonData =  { "Comments":
        [
          { "Id" : 1,"Comment" : "Test comment","Name" : "Yogesh","Child" : 0},
          { "Id" : 2,"Comment" : "Test comment II","Name" : "Yogesh","Child" : 0}
        ]
        };
    var html = "";    
    for (var i = 0; i < JsonData.Comments.length; i++) {
      comment = JsonData.Comments[i];
      html += "Id: " + comment.Id;
      html += " Comment: " + comment.Comment;
      html += " Name: " + comment.Name;
      html += " Child: " + comment.Child;
      html += "<br/>";
    }
alert(html);

您可以使用$.each:

var html = ""; 
$.each(parsedJSON.Comments, function(i, comment) {
   html += "Id: " + comment.Id;
   html += "Comment: " + comment.Comment;
   html += "Name: " + comment.Name;
   html += "Child: " + comment.Child;
   html += "<br/>";
}

或者，您可以使用$.map:

var html = $.map(parsedJSON.Comments, function(comment, i) {
   return "Id: " + comment.Id +
          "Comment: " + comment.Comment +
          "Name: " + comment.Name +
          "Child: " + comment.Child + 
          "<br/>";
}).join('');

Comments持有一个包含两个元素的数组。

{ "Comments" : [ { 1 }, { 2 }]  ...

所以你可以用访问它

for (var i = 0, len = parsedJSON.Comments.length; i < len; i++) {
    html += "Id: " + parsedJSON.Comments[i].Id;
    html += "Comment: " + parsedJSON.Comments[i].Comment;
    html += "Name: " + parsedJSON.Comments[i].Name;
    html += "Child: " + parsedJSON.Comments[i].Child;
    html += "<br/>";
}
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