Thread: Between 100 and 200.

So i wanted to write a code that, when it starts, prints out numbers between 100 and 200 that can be devided between 4 or 5 but not both!
Really hard to figure out how i should go about doing so.

Any tips?

Nothing.. i am stuck and i don't know what to do xD

Hint: Modulus operator...

I agree with tokugawa modulus would be the best way

public static void main(String[] args) {
 
		int number = 0;
 
		for (int i = 200; i > 100; i--) {
			i = i / 4 ^ 5;
			i = number; 
		}
 
		System.out.println(number);
 
	}
 
}

This is what i came up with really quick.
I am not that great with modulus. But i will try!
Btw the code doesnt even work.. it skips the for loop and just says that my sum is 0.

Originally Posted by Norm

I don't see a variable named sum.

The variable: number is given a value of 0, its value is never changed so that the print statement will print a 0.

What does the code in post#9 have to do with the assignment given in post#1?

Why does the loop go from 200 to 100? vs the other way?

I meant "number".
I know that it doesn't change. Trying to figure it out with modulus rn.
The assignment was that i needed numbers that go from 100 to 200 or 200 to 100 that devide by 4 or 5 but not both
and which gives me the end values. Sorry if i am making this difficult but english isn't my main language and i am trying to
solve this. Haha!
But i will take any help.

Okay so i followed both of your steps.
I can get the numbers that i am searching for!
However before i did that i took, ex, 104 / 4 = 26.
And then the highest which would be 195 / 5 = 39.
I then used those as start and end points and then just took those
times 4 or 5.

Works but i am guessing that there is a better way to do this!
Also i don't believe that every number cannot be divided by both 4 and 5
at the same time.

	public static void main(String[] args) {
 
		for (int i = 26; i <= 39; i++) {
			int numbers = i;
			int numbers1 = i; 
			numbers = 4 * numbers;
			numbers1 = 5 * numbers1;
			System.out.println(numbers);
			System.out.println(numbers1);
 
		}
 
	}
}

Originally Posted by Norm

Can you post the program's output? Have you tested the results manually?


What is the logic for using those numbers?
Why test with such a short range of numbers for the loop? What happens when the code uses 100 and 150 for the loop control vs 26 and 39?

For example
100 is divisible by both 4 and 5
104 by 4 not 5
105 by 5 not 4

These are the numbers that you program should find.

Before trying to write any more code, make the list of steps the code should take to solve the problem and post it here so we can help you work out the logic.

What i think it should do.
1. The program should know that it only can choose from 100 to 200.
2. It should be able to print out every value from 100 to 200 (which it can if we begin from scratch).
It isn't too hard to do.
3. It should be able to take the numbers that are divisible by 4.
4. Print those out!
5. It should be able to take the numbers that are divisible by 5.
6. Print those out.
7. An if statement saying if a value of a divisible both can be divided by 4 and 5
then delete that value.

Something along those lines i believe.

Originally Posted by jim829

The fundamental question still remains.

Do you know how to determine if a number is evenly divisible by another number?

That is essential to completing the assignment. Doing your multiplication solution won't work and is probably not in the spirit of the assignment.

Regards,
Jim

No i do not.

And no it isn't in the spirit of the assignment :/

So i feel rather stuck atm.

Originally Posted by Norm

Write a small test program with a loop (say 0 to 20) that prints out the value of the loop index with some modulus value:
For example

   System.out.println("i=" + i + " mod 4= " + (i % 4));

The print out will show you what is returned by modulus.

So what i get is:

i = 0 mod 4 = 0
i = 1 mod 4 = 1
i = 2 mod 4 = 2
i = 3 mod 4 = 3
i = 4 mod 4 = 0
i = 5 mod 4 = 1
i = 6 mod 4 = 2
i = 7 mod 4 = 3
i = 8 mod 4 = 0
i = 9 mod 4 = 1
i = 10 mod 4 = 2
i = 11 mod 4 = 3
i = 12 mod 4 = 0
i = 13 mod 4 = 1
i = 14 mod 4 = 2
i = 15 mod 4 = 3
i = 16 mod 4 = 0
i = 17 mod 4 = 1
i = 18 mod 4 = 2
i = 19 mod 4 = 3
i = 20 mod 4 = 0

public class Test1 {
	public static void main(String[] args) {
 
		for (int i = 0; i <= 20; i++) {
			System.out.println("i = " + i + " mod 4 = " + (i % 4));
		}
 
	}
 
}

So what we are seeing here is that when something can be divided by 4 without having values coming out after it then it turns out to be 0.
So 4 goes in 8 two whole times but it also goes in 9 two whole times but it leaves out 1. Just using those as examples.

So i get that part. In other words... i need to make a code that does the modulus of numbers between 100 and 200 without begin able to
divide by both 4 and 5 but that also won't leave numbers behind. Because then it won't divide as we want it to.

Am i right in that assumption? Or atleast on the right track?

Originally Posted by Norm

When the mod value is 0, that means the number is evenly divisible. Use that test to determine if a number is divisible.
The assignment needs to test if a number is divisible by 4 and if divisible by 5.

What is the logic for the program? Each number needs two tests using: mod 4 and mod 5

Try writing a program like jim829 suggested in post#12

public class Test1 {
	public static void main(String[] args) {
 
		for (int i = 104; i <= 196; i++) {
			if ((i % 5 == 0) && (i % 4 == 0)) {
				System.out.print("");
			} else if ((i % 4 == 0) ^ (i % 5 == 0)) {
				System.out.println(i);
 
				//System.out.println("i = " + i + " mod 4 = " + (i % 4));
			//} else if (i % 5 == 0) {
				//System.out.println("i = " + i + " mod 5 = " + (i % 5));
			}
 
		}
 
	}
 
}

Got it to work! Thanks guys.