EASY

Calculator

An electronic calculator is typically a portable electronic device used to perform calculations, ranging from basic arithmetic to complex mathematics.

Checklist

  • Your demo and repository URLs are correct.
  • You have completed all of the user stories.
  • Your site is deployed up and running.
  • Sensitive data is not publicly visible.

An electronic calculator is typically a portable electronic device used to perform calculations, ranging from basic arithmetic to complex mathematics. In this problem you will create a calculator that supports basic arithmetic calculations on integers.

Constraints

Do not use the eval() function to execute calculations

User Stories

  • User can see a display showing the current number entered or the result of the last operation.

  • User can see an entry pad containing the following buttons:

    • Digits 0-9

    • Operations (addition, subtraction, multiplication, division)

    • Equal

    • AC

  • User can click on an operation button to display the result of that operation on:

    • the result of the preceding operation and the last number entered OR

    • the last two numbers entered OR

    • the last number entered

  • User can click the 'AC' button to clear all internal work areas and to clear the display.

  • User can see 'ERR' if the user tries to divide by 0.

Bonus features

  • User can click a '+/-' button to change the sign of the number that is currently displayed.

  • User can see a decimal point ('.') button on the entry pad to that allows floating point numbers up to 3 places to be entered and operations to be carried out to the maximum number of decimal places entered for any one number.

  • Add a “backspace” button, so the user can undo if they click the wrong number.

  • Add keyboard support.

Useful links and resources

Example projects