For loop in a for loop confusion

[Franklin Marquette]

Hey programming peeps - I am reading "Head First Java" and am on page 121 - one of the activities has you put in a line of code into a larger program and figure out what the output is - I cannot figure out how they got the outputs that they did - here is one of the input/output answers:

class MixFor5 {
  public static void main(String[] args) {
    int x = 0;
    int y = 30;
    for(int outer = 0; outer < 3; outer++){
      for(int inner = 4; inner > 1; inner--) {
        x = x+3;
        y = y-2;
        if (x == 6) {
          break;
        }
        x = x+3;
      }
    y = y-2;
    }
  System.out.println(x + " " + y);
  }
}

The input line of code that I put in is the "x = x+3;". They say that the output of that will be "54 6" and I get nowhere near that.

THANKS for the help!

[Joanne Neal]

Franklin Marquette wrote:They say that the output of that will be "54 6" and I get nowhere near that.

So what do you get ? I just ran that code and I get the expected output.

[Franklin Marquette]

Well yes if I actually run and compile the code I get that - but this was an exercise where I was supposed to figure out the output in my head - so I was wondering why that is the output - I get "18 22" which is not even close to correct.

[Campbell Ritchie]

Don't try it in your head. Write it down and you get something like this:-

initial values of variable i = 3, j = 99
start outer loop test i < 6: true
increment i by 3: i = 6, j = 99
start inner loop test j > 0; true
decrement j by 55: j = 44, i still = 6
etc etc etc

Obviously that is for the other exercise on page 8375873487536

[Franklin Marquette]

Okay cool - I get it now - I just wasn't running the inner for loop again every time the outer for loop incremented - THANKS for the help!

[Campbell Ritchie]

Well done