Can someone help me? Nested for-loop

Processing Beginners
1

I want to combine these two lines but I don’t know how to.

for (int x=940; x<1001; x+=30);
for (int y=53; y<234; y+=30)

1 Like
2

Hello, your mistake might be the ; after the first line

Delete this

2 Likes
3

Chrisir is right, the semicolon ends the first statement so you have two single loops rather than a double loop. I also suggest that you use { } to delineate the code blocks like this

for (int x=940; x<1001; x+=30) {
  for (int y=53; y<234; y+=30) {
    // code to be executed in double loop
  }
}

Although the {} are not required if the code to be executed is a single statement I suggest you use them anyway because they

  • make it clear which code is included in the loops
  • make it easier to add / remove / change debug code inside the loops
  • reduces the risk of logic errors
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4

typical example


void setup() {
  size(1200, 900);
}//func 

void draw() {
  for (int x=940; x<1001; x+=30) {
    for (int y=53; y<234; y+=30) {
      rect(x, y, 20, 20);
    }
  }
}//func 
//
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5

The problem is the ; at the end of the 1st for loop, which is making it a an already complete statement block, w/o incorporating the 2nd for loop: :face_with_monocle:

for (int x = 940; x < 1001; x += 30)
  for (int y = 53; y < 234; y += 30) {
  }

Another way (my fav btW): :wink:

for (int x = 940; x < 1001; x += 30)  for (int y = 53; y < 234; y += 30) {
}
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6

Hello,

Welcome to the Processing Community

Some resources:

:)

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