I'm terribly sorry about going so far off-topic, but I am ripping my hair out right now and I've got nowhere else to go.

A friend of mine boasted she'd made a JavaScript cash register so I decided to try and make one of my own. I got it working with some very basic, repetitive code. I wanted to challenge myself and streamline it today, but I'm running into problems with it. I have declared global variables cashNumber and costNumber. Both of which are set to 0.


var cost; var costNumber = 0; var cash; var cashNumber = 0; var cashBack; var costText = ("Cost of merchandise"); var cashText = ("Cash Paid");

function costPrompt() { dataPrompt(cost, costText, costNumber, costPrompt); }

function cashPrompt() { dataPrompt(cash, cashText, cashNumber, cashPrompt); }

function dataPrompt(x, y, z, a) { x = prompt (y); z = parseFloat(x); console.log (z); console.log (a); if (isNaN(z)) { alert ("That's not a number, cumface. Try again."); a(); } }



console.log ("cashNumber " + cashNumber); console.log ("costNumber " + costNumber);

Can any one explain to me why the changes made to cashNumber and costNumber inside dataPrompt does not change outside the function, even though the variable is global?