For Loop Doesn't Work Right

Question

Why doesn't this for loop count the right number of times? If I set the variable runs to 3, the loops runs 4 times. (One extra case.)

Thanks in advance!

for (int i = runs; i >= 0; i--)
{
   System.out.println("Input Duration of Trip");
   Scanner timeCalc = new Scanner(System.in);
   System.out.print("Hours ==> ");
   int hour = timeCalc.nextInt();
   System.out.print("Minutes ==> ");
   int minute = timeCalc.nextInt();
   System.out.println("You entered: " + hour + " hour(s) and " + minute + " minutes");
   System.out.println();
   time = convertHoursMinutesToDouble(hour, minute);
   totalTime += time;
}

Mike Christensen · Accepted Answer · 2011-11-30 22:39:37Z

5

The loop runs for values:

That's 4 times.

If you want it to run for values 3, 2 and 1, you can change your for loop to:

for (int i = runs; i > 0; i--)

or

for (int i = runs; i >= 1; i--)

answered Nov 30, 2011 at 22:39

Mike Christensen

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Comments

Griffin · Accepted Answer · 2011-12-01 01:36:58Z

1

Your mistake is in

i>=0

What the code is doing is going "Ok, i is going to be equal to three. Now, let's see, ok, back up again, subtract one, i =2... subtract one i=1... Now tricky tricky it SKIPS the termination part of the code because it looks at it first BEFORE substracting one so i=0, ok WAIT i=0 so STOP."

Solution?

for (int i = runs; **i >= 1**; i--)

This mistake always messes me up. Hope the whole "through the mind of the computer thing" doesn't bother you. That's how I tend to think.

Happy coding!

answered Dec 1, 2011 at 1:36

Griffin

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Comments

xbrady · Accepted Answer · 2011-11-30 22:42:17Z

1

i == 3
i >= 0
println

i--
i == 2
i >= 0
println

i--
i == 1
i >= 0
println

i--
i == 0
i >= 0
println

That was 4 times. You need your condition to be: i > 0

answered Nov 30, 2011 at 22:42

xbrady

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Comments

Sid Malani · Accepted Answer · 2011-11-30 22:39:22Z

0

Because you have set greater than or equal to...

So starts at 3 and goes, 2,1,0.

answered Nov 30, 2011 at 22:39

Sid Malani

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