teaching myself C++ prob.

Hi, I hope I got this code tab thing right?
anyway, I want to make this programme, which i am following an exercise out of a book! If the first number is a multiple of the second. Sometimes it works sometimes it dont, what am I doing wrong? In easy terms please

Code:

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#include <iostream>

using namespace std;

int num1;
int num2;
int answer;

int main()
{
        cout << "Enter two numbers to find the multiple of each other" << endl;
        cout << "Enter number 1" << endl;
        cin >> num1;
        cout << "Enter number 2" << endl;
        cin >> num2;

        answer = num1 % num2;

        if( answer == 1 )
                cout << num1 <<" and " << num2 << " are NOT multiples of each other" << endl;

        if( answer == 0 )
        cout << num1 <<" and " << num2 << " ARE multiples of each other" << endl;

        return 0;
}

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Thanks

your problem is that the answer can be something other than 1, and it still could not be a multiple....for instance, 11/4...its 2 with a modulus of 3....it wont display anything because of that...

you can just have it like this.

Code:

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if (answer == 0)
    cout << num1 <<" and " << num2 << " ARE multiples of each other" << endl;

else
    cout << num1 <<" and " << num2 << " are NOT multiples of each other" << endl;

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edit: as far as your code thing goes, you have the backslash the wrong way, it should be /

edited for reverse outputs

code needs to be CODE in the tags.

Quote:

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Originally posted by RoD
code needs to be CODE in the tags.

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It was, just the wrong slash being used though. I've fixed it now.

when i was looking a sec ago he had [code] not [CODE]

Quote:

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Originally posted by RoD
when i was looking a sec ago he had [ code ] not [ CODE ]

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capitilization doesn't matter on code tags

Code:

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this was done with a lowercase code and /code

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i honestly didn't know that, cool thnx for the info.

Might want to declare your variables inside of main(). Although in this program it really doesn't matter, but it is better to stay away from global variables.

Your code may not produce expected results. What happens when i enter 6 for the first number and 100 for the second. It divides 6/100 in integer division thats 0. This will make it happily report that 6 and 100 are multiples of each other. How you gonna fix it? I could tell you but its simple enough to see how.

Use a float data type instead...

Quote:

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It divides 6/100 in integer division thats 0.

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Quote:

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Use a float data type instead...

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I may be wrong, but I didn't see any division anywhere in the code. The only thing that comes close is the modulus. There's no reason to use a float.

You dont see the division then u cant understand what operator % does then. It performs a division, throws away the quotient and return the remainder.

6/100 = 0.06 or 0 as integer division.

6 and 100 are multiples.

Are they? I dont think so. Cmon use ur head. Its not there just to give u something to look at in the mirror.

edit...

Also using a float is the WRONG answer..... Its even simpler. You just need to think about it a little. why does the calculation go wrong if you enter 6 then 100 but go right if you enter 100 then 6.
Thats a big clue!

Quote:

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Originally posted by Stoned_Coder
You dont see the division then u cant understand what operator % does then. It performs a division, throws away the quotient and return the remainder.

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Your knowledge of how the modulus operator works is correct, and 6 / 100 will return 0, but 6 % 100 will not return 0. It will return 6.

Quote:

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why does the calculation go wrong if you enter 6 then 100 but go right if you enter 100 then 6.

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The calculation doesn't go wrong. 6 % 100 is a totally different question than 100 % 6.

However, part of the program is a bit misleading. For example, take 32 and 64. 32 % 64 will return 32, but 64 % 32 will return 0. This is because 64 is a multiple of 32, but 32 is not a multiple of 64.

Code:

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        if( answer == 0 )
        cout << num1 <<" and " << num2 << " ARE multiples of each other" << endl;

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The only time two numbers will be multiples of each other is when the two numbers are the same.

Quote:

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Originally posted by Stoned_Coder
Are they? I dont think so. Cmon use ur head. Its not there just to give u something to look at in the mirror.

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...possibly smoke'n too much cheap ganja has damaged it.

lol my turn for a brainfart day! $$$$ happens then u smoke it!