将数组拼接分配给自身时，Javascript 控制台打印不起作用
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Javascript console printing not working when assigning splice of array to itself
提问by Dragonfly
When I do this:
当我这样做时：
var testArray = ["a","b","c"];
console.log(testArray);
console.log("size:" + testArray.length);
I this this printed in my console:
我这是在我的控制台中打印的：
["a", "b", "c"]
size:3
Which is good. But now when I start splicing with this:
哪个好。但是现在当我开始拼接时：
var testArray = ["a","b","c"];
console.log(testArray);
console.log("size:" + testArray.length);
testArray = testArray.splice(0,1);
This happens to show in my console:
这恰好显示在我的控制台中：
["b", "c", undefined × 1]
size:3
So first question is why does it mess up my printing of the array even though the splice was after the printing? The size is shown correctly but the "a" is gone and I get an undefined at the end.
所以第一个问题是为什么即使拼接是在打印之后它也会弄乱我的阵列打印？大小显示正确，但“a”不见了，最后我得到一个未定义的。
So what I wanted to do was to remove the first item in the array. Basically a shift. So I do this:
所以我想做的是删除数组中的第一项。基本上是一个转变。所以我这样做：
var testArray = ["a","b","c"];
console.log(testArray);
console.log("size:" + testArray.length);
testArray = testArray.splice(0,1);
console.log(testArray);
console.log("size:" + testArray.length);
And this is what gets outputted:
这就是输出的内容：
["b", "c", undefined × 1]
size:3
["a"]
size:1
Not only did the size decrease by 2, it deleted everything but the "a". What is going on?
大小不仅减少了 2，而且删除了除“a”之外的所有内容。到底是怎么回事？
回答by James Kleeh
Dont assign testArray to itself. Simply do:
不要将 testArray 分配给自身。简单地做：
var testArray = ["a","b","c"];
console.log(testArray);
console.log("size:" + testArray.length);
testArray.splice(0,1);
console.log(testArray);
console.log("size:" + testArray.length);
