# Casting in JavaScript

Hi, I'm writing a JavaScript function but I'm doing a mess with casting.

startKey = (parseInt(d2.substr(i,1)) + startKey) * multKey + addKey;

All the variables are numbers, except d2 that is a string.
I want to convert d2.substr(i,1) in a number, but it doesn't work...?

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Commented:
Hi,

Try

(d2.substr(i,1) - 1)

Cheers,
Steve
0
Commented:
Ouch .. sorry

(d2.substr(i,1) - 0)
0
Author Commented:
No... it doesn't work.
"method or property not supported".

This is my whole code, maybe it can help:

function Encrypt()
{

var startKey = 10000;
var multKey = 15000;
var d1 = new String();
var d2 = new String();

d1 = document.fcrypt.campo1.value;
d2 = "";
for (i=0;i<=d1.length-1;i++)
{
d2 = d2 + d1.substr(i,1) ^ (startKey>>8);
startKey = ((d2.substr(i,1)-0) + startKey) * multKey + addKey;
}

document.fcrypt.campo2.value = d2;

}
0
Commented:
Hi,

Yeah d2 is a number as you implicitly cast it to one when you use ^ so you need to change it to a string again.  But beware as your logic may then be wrong as d2 = d2 + d1.substr(i,1) ^ (startKey>>8); will numerically add d1.substr(i,1) ^ (startKey>>8) to d2.

Possible solution:
d2 = d2 + d1.substr(i,1) ^ (startKey>>8);
d2 = d2 + ""
startKey = ((d2.substr(i,1)) + startKey) * multKey + addKey;

Cheers,
Steve.

0

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Commented:
Just thought you may need a combo of both try this also:

d2 = d2 + ""
startKey = ((d2.substr(i,1) - 0) + startKey) * multKey + addKey;
0
Author Commented:
Hi Steve,
Thank you so much.
0
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