multiple if cond.

This is a discussion on multiple if cond. within the C++ Programming forums, part of the General Programming Boards category; Hi, Sorry about this noob question, but I'm obviously retarded or too tired to know why this isn't working: Code: ...

  1. #1
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    multiple if cond.

    Hi,

    Sorry about this noob question, but I'm obviously retarded or too tired to know why this isn't working:

    Code:
    for(int i = 0; i < 20; i++)
    	{
    		if(i%3 || i%5 || i%7)
    			cout << i << endl;
    		
    	}
    The output is the same as if there's weren't no if statement.

  2. #2
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    yup -- it will print every loop value. Why? Pick any number between 0 and 20, then test it yourself.

  3. #3
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    You are actually asking for all values of i which are not divisible by 3, 5 or 7 which means that the first number you would not show is 21 (beyond your range). Perhaps you ment to use && instead?

  4. #4
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    3*5*7 is greater than 20. That statement will only evaluate to false if 'i' is a multiple of 105.
    It is too clear and so it is hard to see.
    A dunce once searched for fire with a lighted lantern.
    Had he known what fire was,
    He could have cooked his rice much sooner.

  5. #5
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    Yes michaels that's what I wanted to do, but isn't || the OR operator? Meaning if i is divisible with 3 or 5 or 7, skip it?

  6. #6
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    Quote Originally Posted by vikernes
    Yes michaels that's what I wanted to do, but isn't || the OR operator? Meaning if i is divisible with 3 or 5 or 7, skip it?
    Yes, but modulous evaluates to false (0) if it is devisible. So the expression is esencially if i is not divisible by 3, 5, or 7.

    So what you really want if either:
    if(!(i%3)||!(i%5)||!(i%7))
    or
    if(!(i%3 && i%5 && i%7))
    Last edited by King Mir; 05-29-2006 at 04:46 PM.
    It is too clear and so it is hard to see.
    A dunce once searched for fire with a lighted lantern.
    Had he known what fire was,
    He could have cooked his rice much sooner.

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