AS3 - 为（...的...）对每个（... ...中） [英] AS3 - for (... in ...) vs for each (... in ...)

问题描述

下面code做同样的事情。是否有每个和的之间的的差异（在... ...）？

  VAR吧：阵列=新阵列（1,2,3）;

对（巴VAR富）{
    跟踪（富）;
}

每个（巴VAR foo2的）{
    跟踪（foo2的）;
}
 

解决方案

没有，他们的没有的做同样的事情。

您for..in循环的输出是

  0
1
2
 

当你的for each..in循环输出

  1
2
3
 

通过键/对象的数组或属性名的指数 for..in循环迭代。一种通过在值each..in循环迭代。你得到上面的结果，因为你的栏阵的结构是这样的：

 栏[0] = 1;
扎[1] = 2;
扎[2] = 3;
 

The following code does the exact same thing. Is there a difference between for each and for (... in ...)?

var bar:Array = new Array(1,2,3);    

for (var foo in bar){
    trace(foo);
}

for each (var foo2 in bar){
    trace(foo2);
}

解决方案

No, they do not do the exact same thing.

The output of your for..in loop is

0
1
2

While the output of your for each..in loop is

1
2
3

A for..in loop iterates through the keys/indices of an array or property names of an object. A for each..in loop iterates through the values. You get the above results because your bar array is structured like this:

bar[0] = 1;
bar[1] = 2;
bar[2] = 3;

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