What is functions

Answer 1

A piece of code that you can call as often as you need it. e.g you want a simple function that squares a number. So you put this code at the top or at the bottom of your script:

function square( number ){
return number*number;
}

Now you can call it as often as you want:

var number1 = 10;
var number2 = square( number1 );
alert( number2 );

This will alert 100.

Answer 2

"A JavaScript function is a block of code designed to perform a particular task.
The main advantages of using functions:
Code reuse: Define the code once, and use it many times.
Use the same code many times with different arguments, to produce different results"

This was copied directly from the course.