Even/Odd number.

This is a discussion on Even/Odd number. within the C Programming forums, part of the General Programming Boards category; How do I check whether the input is even number or whether it's an odd number? When I say the ...

  1. #1
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    Even/Odd number.

    How do I check whether the input is even number or whether it's an odd number?

    When I say the input I mean
    Code:
    char str[] = "12345";
    scanf("%s", str);
    Something like that.

  2. #2
    C++ Witch laserlight's Avatar
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    You can either read it in as an integer, then check if the integer is even/odd, or you can read it in as a string then check if the last character is even/odd.

    For actually determining if a number is even/odd, there are a number of ways. The straightforward way is to check if n % 2 is 0, the other involves bitwise and, which is also straightforward if you think in terms of binary representation.
    Quote Originally Posted by Bjarne Stroustrup (2000-10-14)
    I get maybe two dozen requests for help with some sort of programming or design problem every day. Most have more sense than to send me hundreds of lines of code. If they do, I ask them to find the smallest example that exhibits the problem and send me that. Mostly, they then find the error themselves. "Finding the smallest program that demonstrates the error" is a powerful debugging tool.
    Look up a C++ Reference and learn How To Ask Questions The Smart Way

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    I thought of the num % 2 thing.
    Look what I tried:
    Code:
    char str[] = "12345";
    printf("Enter a number:\n");
    ch = getchar();
    
    if(ch%2 == 0) oddNumber(ch);
    if(ch%2!=0) evenNumber(ch);
    Will it work with getchar? or should I:
    Code:
    ch = scanf("%s", str);
    Is that even possible?

  4. #4
    C++ Witch laserlight's Avatar
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    Will it work with getchar?
    You say you tried. What did you find out?
    Quote Originally Posted by Bjarne Stroustrup (2000-10-14)
    I get maybe two dozen requests for help with some sort of programming or design problem every day. Most have more sense than to send me hundreds of lines of code. If they do, I ask them to find the smallest example that exhibits the problem and send me that. Mostly, they then find the error themselves. "Finding the smallest program that demonstrates the error" is a powerful debugging tool.
    Look up a C++ Reference and learn How To Ask Questions The Smart Way

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    Hmm, I haven't actually compiled and run it, lol
    I just typed it on the same moment lol

  6. #6
    C++ Witch laserlight's Avatar
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    Hmm, I haven't actually compiled and run it, lol
    Then compile what you have and test if it works to your expectations.
    Quote Originally Posted by Bjarne Stroustrup (2000-10-14)
    I get maybe two dozen requests for help with some sort of programming or design problem every day. Most have more sense than to send me hundreds of lines of code. If they do, I ask them to find the smallest example that exhibits the problem and send me that. Mostly, they then find the error themselves. "Finding the smallest program that demonstrates the error" is a powerful debugging tool.
    Look up a C++ Reference and learn How To Ask Questions The Smart Way

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