In the PDE, go to File menu > Examples...
Then start exploring.
You will find lot of sketches using for, if and, more rarely, switch.

Thank you for your help!

But I need something more specific. I need this for tomorrow. Using this 3 commands what can I do??
Please Help!

thank you!

http://processing.org/reference/for.html

I have like this:

int x, y, numberoflines, size, spacing;

void setup() {
  size (200, 200);

  y = height/2;
  size = 20;

  numberoflines = 10;
  spacing = width/numlinhas;
  println(spacing);
}

void draw () {
  background (255);

for(int x=0; x <=width; x++){
  for(int y = 0; y <=height; y++){
    stroke(random(0,255));
    point(x,y);
  }
}
}

Can anyone make something like this but different?

Try my lines with if instead your stroke line (after for)

?!

You don't put an if inside a statement / method call. Java / Processing has a form for that, but I won't confuse you by presenting it. if is a statement by itself,
You replace a normal statement with one with the if, so that the code inside is executed only IF the condition is true.
It is pure logic: if (condition) [then] { execute statements inside the braces; } else { execute other statements; }
The [then] isn't to type, it is here only to show the logic in English.
You can do something like: if (x + y > 200) { stroke(random(0, 127)); } else { stroke(random(128, 255); }
x + y > 200 is an example of condition.
The else is necessary to change back the stroke() that otherwise would apply to the next loops, whatever the condition.
Applied to your sketch:

1. int x, y, numberoflines, size, spacing;
2.  
3. void setup() {
4.   size (200, 200);
5.  
6.   y = height/2;
7.   size = 20;
8.  
9.   numberoflines = 10;
10.   spacing = width / numberoflines;
11.   println(spacing);
12. }
13.  
14. void draw () {
15.   background (255);
16.  
17.   for (int x = 0; x < width; x++) {
18.     for (int y = 0; y < height; y++) {
19.       if (x + y > 200) {
20.         stroke(random(0, 127));
21.       } else {
22.         stroke(random(128, 255));
23.       }
24.       point(x, y);
25.     }
26.   }
27. }

Note that most of the code in setup() isn't used in draw()...
If you need a switch, you can add one before the point() call:

1.       switch (x)
2.       {
3.         case 2:
4.         case 22:
5.         case 122:
6.           stroke(#00FF00);
7.           break;
8.         case 100:
9.           stroke(#0000FF);
10.           break;
11.       }

Change the value in the switch, eg. x + y, change the values of the cases, add some, etc. Play with the code.

After the two Lines with for comes a stroke

Sorry, Phi.lho, same time posting - your's much better...

Thank you so much for your help!

You are welcome!

hi gaping Lotus, can you post your complete resulting Code?

Thanks!  

I was thinking along those lines btw. ---

I hope it worked out for you?  

1. int x, y, numberoflines, size, spacing;
2. void setup() {
3.   size (200, 200);
4.   y = height/2;
5.   size = 20;
6.   numberoflines = 10;
7.   spacing = width/numberoflines;
8.   println(spacing);
9. }
10. void draw () {
11.   background (255);
12.   for (int x=10; x <= width-10; x+=18) {
13.     for (int y=10; y <= height-10; y+=18) {
14.       for (int gain=0; gain <= 10; gain+=4) {     
15.         stroke (0, 66, 170);
16.         if (x>=width/2) {
17.           stroke (244, 0, 0);
18.         }
19.         line (x, y, x+gain, y+14-gain);
20.       }
21.     }
22.   }
23. }

Hi Chrisir,

forget that one, my problem now is this:

I have this code:

int numBolas = 10000;
int tamanhoBolas = 10;
int velocidadeBolas = 4;

float[]largura = new float[numBolas];
float[]altura = new float[numBolas];
float[]xposicao = new float[numBolas];
float[]yposicao = new float[numBolas];
float[]xvelocidade = new float[numBolas];
float[]yvelocidade = new float[numBolas];

in[]colors = new int[numBolas];

void setup() {

  size(800, 600);
  background(0);

  for (int i = 0; i < numBolas; i++) {

    xvelocidade[i] = random(1, velocidadeBolas);
    yvelocidade[i] = random(-velocidadeBolas, velocidadeBolas);
    largura[i] = random(1, tamanhoBolas);
    altura[i] = largura[i];
    xposicao[i] = width/2+random(-width/20, width/20);
    yposicao[i] = height+random(-height/20, height/20);
    colors[i] = color(random(255), random(255), random(255));
    fill(colors[i]);
  }

  noStroke();
  frameRate(100);
}

void draw() {

  background(color(random(255), random(255), random(255)));

  for (int i = 0; i < numBolas; i++) {

    fill(colors[i]);
    ellipse(xposicao[i], yposicao[i], largura[i], altura[i]);
    xposicao[i]+=sin(i)*xvelocidade[i];
    yposicao[i]+=cos(i)*yvelocidade[i];

    if (xposicao[i]+largura[i]/2>=width || xposicao[i]<=largura[i]/2) {
      xvelocidade[i]*=-1;
    }
    if (yposicao[i]+altura[i]/2>=height || yposicao[i]<=altura[i]/2) {
      yvelocidade[i]*=-1;
    }
  }
}

my goal is to put the balls starting to explode every time I click and where I click.
How can I do it?

In mouseClicked()

Hey,

I was searching explosions, but I can't find what I want.
I've to write a for in the mouseClicked function? Using that "dist()"?

thank you so much for your help!

I depends on what you call "explosion". How do you want to make that effect.
Note: never use a for loop to make an animation. See the Technical FAQ...

Replied in the other thread. You should avoid asking the same question in several threads, it isn't practical...