There are a couple of different kinds of loop structures in JavaScript, but a 'for loop' is by far the most popular

​

For Loops have 4 parts: example for loop

 for (let i=0; i<10; i=i+){

  //do something

}

​

FIRST we initialize a variable to keep track of the number = lets call this a counter variable

​

let i=0;

​

Inside loops we tend to use short variable names such as i or j if they are just controlling the 'flow' of the loop.

​

SECOND we define the test condition for the loop, this gets evaluated (tested ) each time the loop is about to start. Our example we are testing if our counter variable is smallet than 10

​

i < 10;

​

THIRD we are (defining a way ) updating the counter variable that then gets evaluated at the end of the loop. We are getting the current value of the variable i and adding 1 to it.

​

i = i + 1; 

​

FORTH, final part, is inside the { } we write the code that the we want repeated. Once the variable counter doesn't 'satisfy' the test i<10 the loop terminates.

​

*/

​

​

function setup() {

  createCanvas(500, 300);

}

​

function draw() {

  background(1,75,220);

  // circle properties

  fill(237, 34, 93);

  noStroke();

  let diameter = 35;

  for(let i=0; i<width/diameter; i=i+1){

    ellipse(diameter/2 +i * diameter,30,diameter,diameter); 

​

// we use the variable values instead of hard coding the numbers. It means we can just update / modify the variable diameter to change the out of the code

  }

​

}