How do I fix my while loop so that it prints out all the numbers between two variables

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Right now my code is able to print out all the numbers between the two int:s "start" and "end". My problem is that the code only works if the variabel start < end and not the other way around. If start > end, then it just loops 2 digits over and over again.

Example: if start = 3 and end = 6 and i run the program, then it will print out "3456"

But if start = 5 and end = 2 and i run the program, then it will print out "545454545454545454545..."

Any guidance would be greatly appreciated!

What I have tried:

public static void runLoop(int start, int end){

while(start != end +1){
if (start > end){
System.out.print(start);
start--;
}
System.out.print(start);
start++;

}
}

Posted 16-Jun-21 6:59am

Rari0002

Updated 16-Jun-21 8:34am

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[no name] 16-Jun-21 14:36pm

You can probably get your head around it if you create 2 loops: one for start < end; another for start > end. You also have to consider when start == end.

2 solutions

Solution 2

Your current code compares the values each time round the loop, so if start is greater than end you print it, reduce the value ... and then print it again, and put it back where it was ...

There are several ways you can do this:
1) Compare start and end before the loop and then have two loops: one where start is greater than end and which runs "down"; one where start is less than end which runs "up".
2) Compare start and end before the loop and set a "direction" variable to 1 or -1. Then make your loop run while start and end are different and change start by "direction" after you print it.

Posted 16-Jun-21 8:34am

OriginalGriff

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Tony Hill · Accepted Answer · 2021-06-16T08:31:00

Solution 1

Try this

Java

public static void runLoop(int start, int end)
{
	if (start < end)
	{
		while(start <= end)
		{
			System.out.print(start);
			start++;
		}
	}
	else
	{
		while(start >= end)
		{
			System.out.print(start);
			start--;
		}
	}
}

Posted 16-Jun-21 8:31am

Tony Hill

Updated 16-Jun-21 8:33am

v2

Comments

Maciej Los 16-Jun-21 15:27pm

:)5ed!