嵌套的For-Loop不能使用Java

Question

I don't know if I'm right here, so if not, please feel free to delete this question.

I want to iterate over a 2-Dimensional Plane of Blocks in a Minecraft Plugin written in Java. Therefore I want to go through every Block in every Row. The following is my code. (Obviously shortened)

package mainiterator;

public class MainIterator {

  public static void main(String[] args) {
    int currentX = -2;
    int currentZ = -2;
    for (; currentX < 2; currentX++) {
        for (; currentZ < 2; currentZ++) {
            //The following should normally be outputted 4*4 Times. (16)
            System.out.println("currentX:" + currentX + " currentZ:" + currentZ);
        }
    }
  }
}

But this only outputs the following:

currentX:-2 currentZ:-2
currentX:-2 currentZ:-1
currentX:-2 currentZ:0
currentX:-2 currentZ:1

So what's the Problem? Please feel free to try it on your own. Thanks in advance!

Greetings,

Max from Germany

Answer 1

The problem is that currentZ is initialized in the wrong place. It should be initialized before the inner loop:

int currentX = -2;
for (; currentX < 2; currentX++) {
    int currentZ = -2;
    for (; currentZ < 2; currentZ++) {
        //The following should normally be outputted 4*4 Times. (16)
        System.out.println("currentX:" + currentX + " currentZ:" + currentZ);
    }
}

You would have avoided this error if you used the for loops as they were meant to be used :

for (int currentX = -2; currentX < 2; currentX++) {
    for (int currentZ = -2; currentZ < 2; currentZ++) {
        //The following should normally be outputted 4*4 Times. (16)
        System.out.println("currentX:" + currentX + " currentZ:" + currentZ);
    }
}