Flash actionscript: moneycounter code not behaving correctly - actionscript-3

Question

I am trying to set up a virtual bus fare vending machine in Adobe Flash (Animate) animation.
The premise is that you must enter exact fare into the slot because drivers don't carry change. Exact fare is $2. The machine accepts denominations of 5 cents, 10 cents, 25 cents, $1, $5, $10 and $20. If anything over $2 is entered, a message pops up saying the "Exact fare only please. Drivers cannot provide change." So in this case, only the 5 cent, 10 cent, 25 cent and $1 denominations will work, but they must be entered to add up to exactly $2.
The code below works correctly for the 25 cent and $1 denominations alone and in combination, but works erratically when 5 cent and 10 cent are used alone or included in combination with the 25 cent and $1. For example, if you try reach $2 by only using the dimes, the total reaches $1.90 but does not payout the fare when you enter the final 10 cents. Instead the pop up "Exact fare only please" message is triggered. If you then add a nickel, the total reaches $1.95 but again will not payout the fare when you enter the final nickel. Instead the pop up "Exact fare only please." message is triggered again.
Entering $1 and then another $1 works perfectly. Entering 8 quarters works as well as does entering $1 and 4 quarters. Can't figure out what the problem is. Would appreciate any help.
Thanks!
Code is below:
var Cash = 00.00
var payola = Money.text = "02.00";
Money.text = "$" + Cash.toFixed(2);
popup.visible = false;
nickel_btn.addEventListener(MouseEvent.CLICK, add5cents);
function add5cents(event:MouseEvent):void
{
nickelcoin_mc.gotoAndPlay ("nickel_pay");
Cash+=00.05;
Money.text = "$" + Cash.toFixed(2);
if(Cash == payola){
setTimeout(delay, 500);
function delay(){
gotoAndStop(46);
}
}
if(Cash > payola){
nickelcoin_mc.gotoAndPlay ("nickel_nopay");
Cash-=00.05;
Money.text = "$" + Cash.toFixed(2);
popup.visible = true;
}
else {
popup.visible = false;
}
}
dime_btn.addEventListener(MouseEvent.CLICK, add10cents);
function add10cents(event:MouseEvent):void
{
dimecoin_mc.gotoAndPlay ("dime_pay");
Cash+=00.10;
Money.text = "$" + Cash.toFixed(2);
if(Cash == payola){
setTimeout(delay, 500);
function delay(){
gotoAndStop(46);
}
}
if(Cash > payola){
dimecoin_mc.gotoAndPlay ("dime_nopay");
Cash-=00.10;
Money.text = "$" + Cash.toFixed(2);
popup.visible = true;
}
else {
popup.visible = false;
}
}
quarter_btn.addEventListener(MouseEvent.CLICK, add25cents);
function add25cents(event:MouseEvent):void
{
quartercoin_mc.gotoAndPlay ("quarter_pay");
Cash+=00.25;
Money.text = "$" + Cash.toFixed(2);
if(Cash == payola){
setTimeout(delay, 500);
function delay(){
gotoAndStop(46);
}
}
if(Cash > payola){
quartercoin_mc.gotoAndPlay ("quarter_nopay");
Cash-=00.25;
Money.text = "$" + Cash.toFixed(2);
popup.visible = true;
}
else {
popup.visible = false;
}
}
one_btn.addEventListener(MouseEvent.CLICK, add$1);
function add$1(event:MouseEvent):void
{
onebill_mc.gotoAndPlay ("one_pay");
Cash+=01.00;
Money.text = "$" + Cash.toFixed(2);
if(Cash == payola){
setTimeout(delay, 500);
function delay(){
gotoAndStop(46);
}
}
if(Cash > payola){
onebill_mc.gotoAndPlay ("one_nopay");
Cash-=01.00;
Money.text = "$" + Cash.toFixed(2);
popup.visible = true;
}
else {
popup.visible = false;
}
}
five_btn.addEventListener(MouseEvent.CLICK, add$5);
function add$5(event:MouseEvent):void
{
fivebill_mc.gotoAndPlay ("five_pay");
Cash+=05.00;
Money.text = "$" + Cash.toFixed(2);
if(Cash == payola){
setTimeout(delay, 500);
function delay(){
gotoAndStop(46);
}
}
if(Cash > payola){
fivebill_mc.gotoAndPlay ("five_nopay");
Cash-=05.00;
Money.text = "$" + Cash.toFixed(2);
popup.visible = true;
}
else {
popup.visible = false;
}
}
ten_btn.addEventListener(MouseEvent.CLICK, add$10);
function add$10(event:MouseEvent):void
{
tenbill_mc.gotoAndPlay ("ten_pay");
Cash+=10.00;
Money.text = "$" + Cash.toFixed(2);
if(Cash == payola){
setTimeout(delay, 500);
function delay(){
gotoAndStop(46);
}
}
if(Cash > payola){
tenbill_mc.gotoAndPlay ("ten_nopay");
Cash-=10.00;
Money.text = "$" + Cash.toFixed(2);
popup.visible = true;
}
else {
popup.visible = false;
}
}
twenty_btn.addEventListener(MouseEvent.CLICK, add$20);
function add$20(event:MouseEvent):void
{
twentybill_mc.gotoAndPlay ("twenty_pay");
Cash+=20.00;
Money.text = "$" + Cash.toFixed(2);
if(Cash == payola){
setTimeout(delay, 500);
function delay(){
gotoAndStop(46);
}
}
if(Cash > payola){
twentybill_mc.gotoAndPlay ("twenty_nopay");
Cash-=20.00;
Money.text = "$" + Cash.toFixed(2);
popup.visible = true;
}
else {
popup.visible = false;
}
}
stop();

Answer 1

This could be a problem caused by floating point numbers. Try putting this in your code and check the console output:
// Expect result to be 0.1
trace(0.3-0.2);
0.09999999999999998
// Adding lots of 5 cent coins. Expect result to be 0.5
trace(0.05 + 0.05 + 0.05 + 0.05 + 0.05 + 0.05 + 0.05 + 0.05 + 0.05 + 0.05);
0.49999999999999994
Your == comparison is failing sometimes because adding floating point numbers together can result in unexpected values. This answer explains the problem well: https://stackoverflow.com/a/3730040/11678918
For your case, try changing your Cash variable into an int, and store the cents instead of the dollars:
var Cash:int = 0;
var payola:int = 200; // 2 dollars
// Add 5 cents
Cash += 5;
// Adding 1 dollar
Cash += 100;
// Printing out the amount in dollars and cents
Money.text = "$" + (Cash / 100).toFixed(2);
// Our exact check is safe now that we avoid floats.
if(Cash == payola) { ... }