Calculator

The purpose of this project, which is the last project of The Odin Project Foundations Course, is to create an on-screen calculator to improve JavaScript, HTML and CSS skills.

The steps I followed for the project:

• Created functions called add, subtract, multiply, divide for the basic math operators. And created a function called percentage to calculate the percent of a number.
• Created a function called operator that takes an operator and two numbers. Used the switch statement to operate according to the operator and to call one of the above math functions on the numbers.
• Added an event listener to the buttons that calls the calculate function every time a button is clicked.
• Created a function called calculate that stores all the values and displays them on the screen. This function evaluates pairs of numbers and one operator at a time. For example, 12 + 7 - 5 * 3 = yields 42.

Calculating this example on the browser console:

• Added an error message to the screen when a number is tried to be divided by 0.
• Disabled the decimal button if there’s already one in the display. The answers with long decimals are rounded using the toFixed() method.
• Created functions called reset that clears all the values and clear that deletes the display value.

Update: Added keyboard support

Live preview is here