在javascript對象內部訪問數組鍵值

Question

我想在javascript中訪問一個數組鍵值。

這裏是我的.js文件：

var contentData = [ 
      { 
       tops: [ 
          { image: "images/top1.jpg" }, 
          { image: "images/top2.jpg" }, 
          { image: "images/top3.jpg" }, 
          { image: "images/top4.jpg" } ] 
      } 
    ]; 

$scope.objectArray = contentData; 
$scope.objectCount = $scope.objectArray[0].length; 

我試圖訪問「頂」內部「contentData內容」，顯示「頂部」數組的長度應該有四個

Answer 1

> var contentData = [ 
...    { 
...     tops: [ 
...        { image: "images/top1.jpg" }, 
...        { image: "images/top2.jpg" }, 
...        { image: "images/top3.jpg" }, 
...        { image: "images/top4.jpg" } ] 
...    } 
...  ]; 
undefined 
> 
> contentData[0].tops.length 
4 

Answer 2

您不指定tops屬性。它應該是：

$scope.objectArray[0].tops.length;