Array.length = 0和阵列之间差异= []？ [英] Difference between Array.length = 0 and Array =[]?

问题描述

有人能解释一下两者之间的概念上的差异。读的地方，第二个通过破坏所有引用现有的阵列和。长度创建新的数组= 0只清空数组。但是，这并不在我的情况下工作。

Can some one explain the conceptual difference between both of them. Read somewhere that the second one creates a new array by destroying all references to the existing array and the .length=0 just empties the array. But it didn't work in my case

//Declaration 
var arr = new Array();

下面一个是循环code，它一次又一次地执行。

The below one is the looping code that executes again and again.

$("#dummy").load("something.php",function(){
   arr.length =0;// expected to empty the array
   $("div").each(function(){
       arr = arr + $(this).html();
   });
});

但是，如果我更换code ARR = [] 代替 arr.length = 0 它工作正常。任何人能解释这里发生了什么。

But if I replace the code with arr =[] in place of arr.length=0 it works fine. Can anyone explain what's happening here.

推荐答案

富= [] 分配给新的数组变量的引用，而其他任何引用不受影响。

foo = [] assigns a reference to a new array to a variable, while any other references are unaffected.

foo.length = 0 删除阵列，它不打其他文献中的一切。

foo.length = 0 deletes everything in the array, which does hit other references.

某处阅读第二个通过破坏现有阵列的所有引用创建新的数组

Read somewhere that the second one creates a new array by destroying all references to the existing array

这是倒退。它创建了一个新的数组，并不会破坏其他引用。

That is backwards. It creates a new array and doesn't destroy other references.

var foo = [1,2,3];
var bar = [1,2,3];
var foo2 = foo;
var bar2 = bar;
foo = [];
bar.length = 0;
console.log(foo, bar, foo2, bar2);

给出了：

[] [] [1, 2, 3] []

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