Javascript array

I am simulating a 4 dimensional array and am having a small issue which I can't seem to figure out.

As an example:

var test = [];

test[0000] = 1;
test[0100] = 2;

a = 0+'';
b = 0+'';
c = 0+'';
d = 0+'';

e = a+b+c+d;

alert(e);
alert(test[e]);
alert(test[0000]);

Code (markup):

If you run this javascript I get 3 alerts as follows:

1) 0000
2) Undefined
3) 1



Can anyone explain why that second alert is showing undefined when in theory it's the same as the 3rd one.

 

I guess javascript is using associative arrays with strings, but treating e as a number, so test[e] is undefined.

You can get it worked using strings explicitly:

var test = [];

test['0000'] = 1;
test['0100'] = 2;

a = '0'+'';
b = '0'+'';
c = '0'+'';
d = '0'+'';

e = a+b+c+d;

alert(e);
alert(test[e]);
alert(test['0000']);	

Code (markup):

 

heh.... of course, I'm an idiot.... but I guess its hard to think at 1am in the morning.

rep added

 

test[e] is declared wronglyl...