# The usage of modulo: How can I correctly implement it?
**URL:** https://discourse.processing.org/t/the-usage-of-modulo-how-can-i-correctly-implement-it/7494
**Category:** Coding Questions
**Created:** [January 14, 2019, 8:52am UTC](https://discourse.processing.org/t/the-usage-of-modulo-how-can-i-correctly-implement-it/7494 "2019-01-14T08:52:32Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@anon98404100](https://discourse.processing.org/u/anon98404100)
#### Post date: [January 14, 2019, 8:52am UTC](https://discourse.processing.org/t/the-usage-of-modulo-how-can-i-correctly-implement-it/7494/1 "2019-01-14T08:52:32Z")
In my way of learning P5.js I enountered the ‘Modulo’ function. I did some reading into it, but I fail to understand HOW I should be looking at it and using it.
I have a number ‘generator’ that generates the number 1 to 100. Our task is: For every multiplication with 5 (5, 10, 15…) a name should appear and we were asked to use modulo.
I understand that you use the ‘%’ to divide 2 numbers, but fail to understand out how I can properly use it.
Any explanation that can be given would be appreciated!
```auto
var gooi = 0;
function setup () {
createCanvas (300, 1500);
noLoop();
}
function draw () {
textSize(12);
// i = hoogte van tekst plaatsing
for (i = 0; i < 1000; i += 10) {
gooi += 1;
text( '(' + gooi + ')' + ' ' + 'gegooid: ' + gooi, 10, (i + 20));
}
}
```
---
### Author:  [@GoToLoop](https://discourse.processing.org/u/GoToLoop)
#### Post date: [January 14, 2019, 9:00am UTC](https://discourse.processing.org/t/the-usage-of-modulo-how-can-i-correctly-implement-it/7494/2 "2019-01-14T09:00:47Z")
> [@anon98404100](#):
>
> For every multiplication with 5 (5, 10, 15…) a name should appear and we were asked to use modulo.
`!(i % 5) && print(name);`
> **[% (modulo) / Reference](https://processing.org/reference/modulo.html)**
>
> Calculates the remainder when one number is divided by another. For example, when 52.1 is divided by 10, the divisor (10) goes into the dividend (52.1) five times (5 \* 10 == 50), and there is a remain…
> **[Expressions and operators - JavaScript | MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators)**
>
> This chapter documents all the JavaScript language operators, expressions and keywords.
---
### Author:  [@anon98404100](https://discourse.processing.org/u/anon98404100)
#### Post date: [January 14, 2019, 9:18am UTC](https://discourse.processing.org/t/the-usage-of-modulo-how-can-i-correctly-implement-it/7494/3 "2019-01-14T09:18:20Z")
@GoToLoop
So if I understand correctly, you use the remainder for your calculations?
like in the example of 52.1 % 10, your remainder is 2.1 and you use that?
---
### Author:  [@GoToLoop](https://discourse.processing.org/u/GoToLoop)
#### Post date: [January 14, 2019, 10:11am UTC](https://discourse.processing.org/t/the-usage-of-modulo-how-can-i-correctly-implement-it/7494/4 "2019-01-14T10:11:40Z")
> [@anon98404100](#):
>
> Like in the example of `52.1 % 10`, your remainder is `2.1` and you use that?
AFAIK, your loop `for (i = 0; i < 1000; i += 10) {` generates only whole values for the variable _i_.
`!(i % 5) && print(name);` won’t work if _i_ is a fractional value!
---
### Author:  [@kll](https://discourse.processing.org/u/kll)
#### Post date: [January 14, 2019, 10:35am UTC](https://discourse.processing.org/t/the-usage-of-modulo-how-can-i-correctly-implement-it/7494/5 "2019-01-14T10:35:09Z")
a practical app for use
modulo and floor to make a GRID
in a one line FOR loop
```auto
// https://discourse.processing.org/t/scalable-grid-with-rectangles/7256
int x = 10, y = x, w = 20, h = w;
int grid = 24, many = grid*grid;
void setup() {
size(500, 500);
stroke(0, 0, 200);
fill(0,200,0);
}
void draw() {
background(200,200,0);
for (int i = 0; i < many; i++) rect(x+(i%grid)*w, y+(floor(i/grid))*h, w, h);
}
```
---
### Author:  [@jeremydouglass](https://discourse.processing.org/u/jeremydouglass)
#### Post date: [January 29, 2019, 6:22pm UTC](https://discourse.processing.org/t/the-usage-of-modulo-how-can-i-correctly-implement-it/7494/6 "2019-01-29T18:22:29Z")
A very common use of [modulo](https://processing.org/reference/modulo.html) in Processing is to perform an action every nth frame.
So, if I wanted to do something every 7 frames:
```auto
int step = 7;
void draw(){
if(frameCount%step == 0){
print(frameCount, " ");
}
}
```