与JS数组长度斗争

Question

我有这段代码，当你看到它时，似乎逻辑运行如下：

我创建了3个空数组，我向bankSelectedData添加了一个值，我打印出了值，显然bankSelectedData现在为1而bankSelectionArrayCurrent长度为0，但后来我说：

bankSelectionArrayPrevious = bankSelectionArrayCurrent;

所以我将bankSelectionArrayPrevious转换为bankSelectionArrayCurrent。当我检查bankSelectionArrayPrevious的大小是'1'时？这怎么可能？

var bankSelectionArrayCurrent = new Array();
var bankSelectionArrayPrevious = new Array();
var bankSelectedData = new Array();
    bankSelectedData.push("value1");

alert("bankSelectionArrayCurrent length: "+bankSelectionArrayCurrent.length);
alert("bankSelectedData length: "+bankSelectedData.length);

if(bankSelectedData.length != bankSelectionArrayCurrent.length){
    bankSelectionArrayPrevious = bankSelectionArrayCurrent;
    bankSelectionArrayCurrent.length = 0

    alert("previousSize: "+bankSelectedData.length);
    alert("currentSize: "+bankSelectionArrayCurrent.length);
}​

感谢您的任何建议！

Answer 1

您的代码永远不会更改“bankSelectedData”，因此在您添加第一个值后，其长度将保持为1。

您的代码不包含任何长度为“bankSelectionArrayPrevious”的alert()来电。

Answer 2

您的提醒错误。它应该是：

alert("previousSize: "+bankSelectionArrayPrevious.length);

Answer 3

你在哪里

alert("previousSize: "+bankSelectedData.length);

也许你的意思是：

alert("previousSize: "+bankSelectionArrayPrevious.length);