Question

Here is the code –

int i = 0;
    
System.out.printf( "\n%d\n\n", i );  // show variable i before loop
    
for( i = 0; i < 8; i++ )
{
    System.out.printf( "%d\t", i );
}
    
System.out.printf( "\n\n%d\n", i );   // show variable i after loop

Here is the output –

0

0 1 2 3 4 5 6 7

8

My problem arises when I want to use the variable i after the exit of the for loop. I would assume that i is reading 7, the 8th increment in zero based counting but it actually reads as 8!!! One more increment to variable i has been made on loop exit.

In order to remedy this I would have to do something like i– at the end of the loop and before using it in any further code. This seems to me to make the code harder to understand.

Is there a better solution?

Answer 1

When i is 7, the condition i < 8 is still fulfilled, so there is no reason to exit the loop.

It is not very clear to declare the loop variable before the loop and use it afterwards anyway. Rather, consider declaring the loop variable with the loop statement.

int numIterations = 8;
for(int i = 0; i < numIterations; i++) {
    // ...

}
// continue doing something with numIterations, or numIterations-1

If using numIterations-1 really bothers you, you could also instead use int maxCounter = 7 and use i <= maxCounter instead as loop invariant.