### Lesson Notes 1X

by golan @ 2:20 pm September 7, 2011

For Loop Example:

```size (300, 300); background (255,200,200); strokeWeight (3); stroke(0,0,0);   float foo = 164; float mySpacing = 16; int nLines = 12;   for (int i=1; i<=nLines; i=i+1) {   float greyVal = map(i, 1,nLines, 0,255); stroke (greyVal);   line (10, i*mySpacing, foo, i*mySpacing); ellipse (foo, i*mySpacing, 10,10); }```

For Loop with Random numbers:

```size (300, 300); background (255,200,200); strokeWeight (2);   for (int i=0; i<10; i++) { float rx = i*30 + 15; float ry = random(140, 160);   float rGray = random(0, 255); fill(rGray); ellipse (rx, ry, 40, 40) ; }```

Live interaction with iteration (for loop)

```void setup() { size (400, 400); }   void draw() { background(255, 200, 200); strokeWeight(2); smooth( );   for (int i=1; i<40; i++) {   if (i == 17){ // equality test. Note the double-equals !!!! stroke(255,0,0); line (i*10, 0, mouseX, mouseY); } else { stroke (0,0,0); ellipse(i*10, mouseY, 10,10); }   } }```

Conditional testing: Equality testing in a for loop

```void setup() { size (400, 400); }   void draw() { background(255, 200, 200); strokeWeight(2); smooth( );   for (int i=1; i<40; i++) {   if (i == 17){ // equality test. Note the double-equals !!!! stroke(255,0,0); line (i*10, 0, mouseX, mouseY); } else { stroke (0,0,0); ellipse(i*10, mouseY, 10,10); }   } }```

Embedded iteration

```size (400, 400); background(255, 200, 200); fill(255, 0, 0);   for (int x=1; x<20; x=x+1) { for (int y=1; y<20; y=y+1) { fill (x*20, y*20, 0); ellipse (x*20, y*20, 10, 10); } }```