# Change line() color in a nested while-loop
**URL:** https://discourse.processing.org/t/change-line-color-in-a-nested-while-loop/7421
**Category:** Coding Questions
**Tags:** homework
**Created:** [January 11, 2019, 3:06pm UTC](https://discourse.processing.org/t/change-line-color-in-a-nested-while-loop/7421 "2019-01-11T15:06:42Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@anon98404100](https://discourse.processing.org/u/anon98404100)
#### Post date: [January 11, 2019, 3:06pm UTC](https://discourse.processing.org/t/change-line-color-in-a-nested-while-loop/7421/1 "2019-01-11T15:06:42Z")
I am doing a small assignment that requires the following:
I have to create a while-loop that draws 30 lines on-screen. Line number 7 and line number 23 should be colored red.
Because I am still trying to figure things out, I try to color the 2 nearest lines from stroke(0); to stroke(255);, but no matter what I try, I cannot get the 2 lines to change color
In this example I tried nesting a while loop, which so far doesn’t work. I also tried removing te nested while loop and add an “if” statement with the same variables (x == 40 && x == 60) but still nothings happens. What can I do to fix this?
```auto
var x = 20;
var stap = 20;
var stop = 600;
function setup () {
createCanvas (700, 700);
}
function draw () {
stroke(0);
while(x < stop) {
line(x, 60, x, 80);
x += stap;
while (x == 40 && x == 60) {
stroke(255);
}
}
}
```
---
### Author:  [@Whahahahaha](https://discourse.processing.org/u/Whahahahaha)
#### Post date: [January 11, 2019, 3:58pm UTC](https://discourse.processing.org/t/change-line-color-in-a-nested-while-loop/7421/2 "2019-01-11T15:58:12Z")
@anon98404100 a few things:
- Processing, and I strongly believe P5.js as well, only update their screens at the end of the draw loop
- You’re changing the stroke AFTER you draw the line, then draw restarts, set stroke to 0 and draws again
- while (or if for that matter) x == 40 AND x == 60 never happens. x cannot be both 40 And 60 at the same time, use or: ||
Here’s your code with the proper changes, but note it does not draw all the lines at once, for that you’d need to store the x values in an array of some sorts and use a for loop to draw them
```auto
var x = 20;
var stap = 20;
var stop = 600;
function setup () {
createcanvas(700, 700);
}
function draw () {
stroke(0);
if (x < stop) {
if (x == 40 || x == 60) {
stroke(255);
}
line(x, 60, x, 80);
x += stap;
}
}
```
Hope this solves your question 🙂
---
### Author:  [@anon98404100](https://discourse.processing.org/u/anon98404100)
#### Post date: [January 11, 2019, 4:17pm UTC](https://discourse.processing.org/t/change-line-color-in-a-nested-while-loop/7421/3 "2019-01-11T16:17:51Z")
@Whahahahaha
Thank you! it works indeed 🙂
I added the ‘while’ loop that I needed for my assignment to it 🙂
```auto
while (x < stop) {
stroke(0);
if (x == 40 || x == 60) {
stroke(255);
}
line(x, 60, x, 80);
x += stap;
}
}
```
and got the desired effect I was looking for :).
Sorry if the question is stupid, but could you tell me why I cannot put the
```auto
line(x, 60, x, 80);
x += stap;
```
right under the x\
### Author:  [@Kevin](https://discourse.processing.org/u/Kevin)
#### Post date: [January 11, 2019, 6:18pm UTC](https://discourse.processing.org/t/change-line-color-in-a-nested-while-loop/7421/4 "2019-01-11T18:18:45Z")
If you post to multiple sites, please link between those posts so we know what help you’ve already received. This question has also been asked (and answered) here:
>
---
### Author:  [@TfGuy44](https://discourse.processing.org/u/TfGuy44)
#### Post date: [January 11, 2019, 7:39pm UTC](https://discourse.processing.org/t/change-line-color-in-a-nested-while-loop/7421/5 "2019-01-11T19:39:13Z")
A painter does not touch brush to canvas and then pick which color paint to use afterwards.
The painter picks which color paint to use, and then paints with it.
Like a painter, you should pick which color you want your lines to be… and then draw them.
This is why stroke() and fill() calls should come first.
---
### Author:  [@anon98404100](https://discourse.processing.org/u/anon98404100)
#### Post date: [January 11, 2019, 8:29pm UTC](https://discourse.processing.org/t/change-line-color-in-a-nested-while-loop/7421/6 "2019-01-11T20:29:29Z")
Sorry about that. I am used to the fact that I sometimes do not get a response on 1 site, which makes me inclined to post it on another for good meassure.
When i got my first answer on stackoverflow, it unfortunately wasnt the answer I could use (actual javascript and not P5) and later on got the answer here before others started to comment i believe.
But wont happen again. Will stick it to 1 post at a time.
---
### Author:  [@jeremydouglass](https://discourse.processing.org/u/jeremydouglass)
#### Post date: [January 28, 2019, 8:23pm UTC](https://discourse.processing.org/t/change-line-color-in-a-nested-while-loop/7421/7 "2019-01-28T20:23:46Z")
> [@anon98404100](#):
>
> Will stick it to 1 post at a time
@anon98404100 – you don’t have to stick to 1 post at a time! Just link to those posts.
1. post to [stackoverflow.com](http://stackoverflow.com)
2. post to [processing.org](http://processing.org)
3. on [processing.org](http://processing.org), add a link to the stackoverflow post
4. on [stackoverflow.com](http://stackoverflow.com), add a link to the [processing.org](http://processing.org) post.
That way people can look at both when seeing whta help you have already received, and they won’t waste time repeating others.