Thread: How does this for-while loop works?

Ok, so I got the following code:

Code:

int i,j=1;

for(i=1; i<=3; i++){
  while(j <= i){
    printf("A");
    j++;
  }
  printf("B\n");
  j = 1;
}

The output for this is

AB
AAB
AAAB

My initial expectation for output would be:
AB
AB
AB

But when I remove j = 1 at the bottom of for loop then I get that result. What does j=1 does to this loop so that I get AB AAB AAAB?

Originally Posted by Programmin9

Ok, so I got the following code:

Code:

int i,j=1;

for(i=1; i<=3; i++){
  while(j <= i){
    printf("A");
    j++;
  }
  printf("B\n");
  j = 1;
}

The output for this is

AB
AAB
AAAB

My initial expectation for output would be:
AB
AB
AB

But when I remove j = 1 at the bottom of for loop then I get that result. What does j=1 does to this loop so that I get AB AAB AAAB?

It resets j so that the while loop prints out i number of 'A' then 'B' Without the "j = 1;", j is always one less than i and prints only one 'A'.

Put some extra printf() statements in the code to see the values of i and j as the program executes, or else us a debugger such as gdb to whatch the values as you step through the program.