setup function in javascript code example

Example 1: js function

function name(parameter1, parameter2, parameter3) {
// what the function does
}

Example 2: javascript function

// variable:
var num1;
var num2;
// function:
function newFunction(num1, num2){
	return num1 * num2;
}

Example 3: what does function setup() do in javascript

function setup() {
	create canvas(400, 400)
}

function draw(){
	if(mouseIsPressed){
		fill(0);
}else{
  fill(255)
}
  ellipse(mouseX, mouseY, 80, 80)
}