Chrome开发人员工具阵列长度 [英] Chrome developer tool Array length

问题描述

图像的第一行应该像Array [9]为什么它显示数组[0]

解决方案

看起来你是在你添加对象到数组之前记录数组的输出。就像

  var arr = []; 
 console.log（arr）; 
 arr.push（{}）; // push blank obj 
  

在这里，执行这段代码将导致 Array [ 0] 但它确实包含你的对象，并且如果你有返回一个长度 1 尝试 arr.length 。

如果您有某种将项目推送到数组的异步函数，也会发生这种情况，这会导致同样的情况。例如，

  var a = []; 
 setTimeout（function（）{
.push（{}）; 
.push（{}）; 
}，1000）; 
 console.log（a）; 
  

我认为，这种行为是故意的，Chrome想要证明最初您的Array是空的，稍后，项目会在运行时推送。

Why chrome developer tool showing 0 array length (first line Array[0]) even if there are total 9 objects in it?

At first line of image should be like Array[9] why it is showing Array[0]

In second image array has 13 objects so it is showing Array[13] not Array[0]

解决方案

It seems like you are logging the output of the array before you are adding objects to your array. Something like

var arr = [];
console.log(arr);
arr.push({}); //pushing blank obj

Here, executing this code will result in Array[0] but it does hold your object and will return a length of 1 if you try arr.length.

This might also happen if you are having some sort of Async function which pushes item to your array, which will result in the same thing. For example,

var a = [];
setTimeout(function(){
  a.push({});
  a.push({});
}, 1000);
console.log(a);

I think, this behavior is intentional, where Chrome wants to show that initially, your Array was empty, later on, items were pushed on runtime.

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