Cash Register Demo - floating-point error

[gikf]

Describe the bug
Demo of the Cash Register project has issue with the floating-point error. Causing it display values with error, and in certain situations, for remaining cash to go below $0.

To Reproduce

1. Go to https://cash-register.freecodecamp.rocks
2. Enter 330 and submit.
3. Enter 10 and submit.
4. Enter 4 and submit.
5. Enter 4 and submit.

At the step 3. value below status will include the number with clear floating-point error.
After step 5. in register Nickels are below $0.

Expected behavior
Cash shouldn't go below $0, or be displayed with more than a dozen of digits after the dot.

Screenshots

Additional context

• The least time-absorbing solution is adding toFixed(2) method to two more places:
  

  demo-projects/apps/cash-register/public/script.js

  Line 66 in a712591

  total -= denominations[i];

  
  

  demo-projects/apps/cash-register/public/script.js

  Line 70 in a712591

  result.change.push([reversedCid[i][0], count * denominations[i]]);

• More robust option is saying no to floats and changing more internals to not do calculations on floats.

[obafemitayor]

Created a PR to fix this
#560