Question

I have created some arrays, example yy1, yy2, yy3, etc., and I am able to display the elements of an array using

for (j=0; j < count; j++){
    alert(yy1[j]);
}

and other arrays by changing number, that is yy2, yy3…

How to display the array in a loop, like

for (i=0; i< lengthL; i++){ 
    for (j=0; j < count; j++){
        alert(yyi[j]);
    }
}

That is how to join yy with i.

Please let me know if I am not clear, thanks in advance.

Answer 1

What you are looking for is eval (Warning, Eval is evil!). You can use it to do what you are trying to do but you should rather change the way the data is stored to avoid it. It is very easy in your case (look at other answer for guidance).

var yy1 = [11, 12, 13];
var yy2 = [21, 22, 23, 24, 25];
var yy3 = [31, 32, 33, 34];

for (i = 1 ; i <= 3 ; i++)
{
    var arr = eval("yy" + i);

    for (j = 0 ; j < arr.length ; j++)
    {
        console.log(arr[j]);
    }
}

Demo

You should use Firefox and Firebug so that you can use console.log instead of alert.