Need help with this Loop

Processing Beginners
1

Can anyone tell me what I am doing wrong? I cannot get this to do more than one row.

float randomW;
float randomH;
float row;
float column;


void setup(){
size(400,400);
background(250,250,0);
   
for(int row = 0; row<height; row=row+20)
{
  for(int column = 0; column<width; column=column+20);
  {
randomW = random(5,10);
randomH = random(5,10);

  fill(random(0,256), random(0,256), random(0,256));
  rect(row, column, randomW, randomH);
  }}
}
2 Likes
2

Format your code… maybe in

rect(row, column, randomW, randomH);

you can do

rect(row * 50, column * 50, randomW, randomH);

Also, in your loops

for(int row = 0; row<height; row=row+20){
    for(int column = 0; column<width; column=column+20);{
    }
}

you could use row += 20 and column += 20

3

I tried your suggestions, but it didn’t change. I need it to reproduce and fill the screen with 20 rows / columns. I really thought I coded it right, but clearly I didn’t because it only produces 1 row. Thank you so much for trying to help me.

4

Oh I think the glaring error is the lack of a draw function… put all of your code after size(400, 400) in a

void draw(){
}

function so it refreshes every frame

5

Thank you for catching that. I changed it, and now you can tell that it is looping because all of the rectangles are flashing, but they are still creating only one row at the top.

6 
float randomW;
float randomH;
float row;
float column;

void setup() {
  size(400, 400);
}

void draw() {
  background(250, 250, 0);
  for (int row = 0; row<height; row+=20) {
    for (int column = 0; column<width; column+=20) {
      randomW = random(5, 10);
      randomH = random(5, 10);
      fill(random(0, 256), random(0, 256), random(0, 256));
      rect(row, column, randomW, randomH);
    }
  }
}

You had a stray semicolon here:

 for(int column = 0; column<width; column=column+20);{

See it? Right near the end, between the ) and {?
That ruins the structure of your code, essentially making your column loop do nothing.

1 Like
7

That worked!!! Oh my gosh!!! Thank you so much!!!

8

Is there any way you could look at another problem I am having?

Cant get this to stop at 25 ellipses.

float randomX;
float randomY;
float randomZ;
float randomQ;
int x;

void setup(){
  size(400,400);
  background(250,250,0);   
}
void draw(){
randomX = random(width);
randomY = random(height);
randomZ = random(10,50);
randomQ = random(10,50);

    for (x = 0; x<25; x++)
     
  fill(random(0,256), random(0,256), random(0,256));
  ellipse(randomX, randomY, randomZ, randomQ);
}
1 Like
9

And where’s the curly brace to start this for loop? {?

1 Like