Dealing with the complexities of JavaScript Array lengths

Upon examining this code snippet, the apparent logic seems to be as follows:

Three empty arrays are created. One value is added to bankSelectedData and its length is printed out. Then a line of code sets bankSelectionArrayPrevious equal to bankSelectionArrayCurrent. However, even after this assignment, when checking the size of bankSelectionArrayPrevious, it still displays '1'. How is this possible?


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);
}​

If you have any insights or guidance on how this issue can arise, I'd appreciate it!

Answer №1

When you encounter

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

it's possible that you intended:

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

Answer №2

The value of "bankSelectedData" in your code remains constant, resulting in a length of 1 even after adding the initial value.

No alert() function is used in your code to display the length of "bankSelectionArrayPrevious".

Answer №3

There is an error in your notification. The correct version should read:

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

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