Controlling 2 "for" loops

Question

Hi,
I need a particular control of 2 "for" loops. It goes like this:
for(int j=1;j<5;j+3){
     for(int i=0;i<20;i++){
           //do something
}However, when the for loop for "i" ends it is coming out of both the for loops. I don't want this. But what I want is:
The loop for i should go on till all the 20 iterations of i and then it must go out of the loop and then only j should be incremented.
[Actually I want all possible combinations of i with a single j. ]
Thanks

Answer 1

kooldba wrote:
Hi,
I need a particular control of 2 "for" loops. It goes like this:
for(int j=1;j<5;j+3){
for(int i=0;i<20;i++){
//do something
}However, when the for loop for "i" ends it is coming out of both the for loops. I don't want this. It is only doing this if "do something" includes one of the following:
- labeled break to a label outside of both loops.
- labeled continue to a label outside of both loops.
- return
- an exception being thrown
- j being set to some value >= 5
But what I want is:
The loop for i should go on till all the 20 iterations of i and then it must go out of the loopThat is exactly what is happening, unless "do something" includes one of the following
- break
- continue
- return
- exception being thrown
- i being given other values
and then only j should be incremented.The above code does not have an increment statement for j, so unless j is incremented in "do something", it will never be incremented, and the inner for loop will repeat endlessly.
[Actually I want all possible combinations of i with a single j. ]This is exactly what a properly written nested for loop gives.
Note the difference in the following compared to your j control.
for(int j=1;j<5;j+=3){
     for(int i=0;i<20;i++){
           System.out.println("j=" + j + ", i=" + i);
      System.out.println("incrementing j");
}