FCC-Calculator

This is my advanced front-end project for freecodecamp.com. I put a lot of work into it so i decided to add a version to githubs. The orginal can be seen on codepen.

Built-with

HTML, CSS, JavaScript, and jQuery

Biggest Challenge

The floating point rounding error present in all JavaSctipt math was annoying me, while I was testing my calculator. I came up with this code in an attempt to round off one particular error

function roundoff(string) {
  let ans = string;
  ans = ans.replace(/[+-/*//.]/, "");

  let sum = ans.length - 1;
  
  if (string)
  return (eval(string).toFixed(sum)).replace(/0+$/, '');
}

It solves problems like .45/100, which will be rounded down to the expected value, but doesn't work in all cases.

Other Lessons Learned

1. I had to use the eval() script for this project, so I spent a lot of time reading about the benefits and the potential security risk of using this script. I believe for a calculator where the user input is limited to numbers the security risk is negligible.

2. This project also taught me the value of localizing my assets as links I used in my code have broken down more frequently than I originally anticipated.