Thread: OR statement in C

  1. #1
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    OR statement in C

    Hi,

    Is there such a thing as an OR statement in C?

    For example:

    If (x>0 OR x<10)
    then.....

    Thanks!

  2. #2
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    Yes, replace the OR with || (AND is && in C)

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    Thank you!

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    No problem, I'll bill you later.

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    Keylac, I assume you are a beginner (so am I). Pay attention to the double symbols: && and ||

    You also have the single | and &, which are the bitwise operators for or and and.

    You'll remember from boolean logics:

    0 | 1 = 1
    1 | 0 = 1
    1 | 1 = 1
    0 | 0 = 0

    0 & 1 = 0
    1 & 0 = 0
    1 & 1 = 1
    0 & 0 = 0

    It's an often made beginner's mistake to confuse these operators (logical and bitwise), it 's comparable to

    if (x = 0)

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    another thing ....

    x=6 is often mistaken with x ==6.

    x = 6 means, make x equal 6.

    x == 6 means, "Is x equal to 6?"

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    Quote Originally Posted by x2x3i5x View Post
    another thing ....

    x=6 is often mistaken with x ==6.

    x = 6 means, make x equal 6.

    x == 6 means, "Is x equal to 6?"
    I totally agree with this point, and this is a very good point to mention where most beginner does the mistake. in condition or loop people say something like x=6 means it will, always be true.

    so to reduce what we can do just

    do like this

    Code:
    if (6 ==x)
    Then when ever by mistake we do like

    Code:
    if (6 =x)
    it means the compiler will say than
    error: lvalue required as left operand of assignment
    In my point of view we can do like this also

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    Thanks!

    Thanks everyone for the great info!

  9. #9
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    Okay, now that you got the important, here's some fun trivia:

    If your compiler supports the 1999 edition of the C standard sufficiently, you can #include <iso646.h> and use the or macro instead of ||. (<iso646.h> defines or to be || for you.) That said, there is probably no benefit for you in doing this.
    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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