Why is it that my program does not print for case 1?

This is a discussion on Why is it that my program does not print for case 1? within the C Programming forums, part of the General Programming Boards category; Code: main() { int x=0; switch(x) { case 1: printf( "One" ); case 0: printf( "Zero" ); case 2: printf( ...

  1. #1
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    Why is it that my program does not print for case 1?

    Code:
    main()
    {
    
     int x=0;
     switch(x)
     {
      case 1: printf( "One" );
      case 0: printf( "Zero" );
      case 2: printf( "Hello World" );
     }
     }

  2. #2
    and the Hat of Guessing tabstop's Avatar
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    Because it does. In fact, it will print "OneZeroHello World".

  3. #3
    Guest Sebastiani's Avatar
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    >> Why is it that my program does not print for case 1?

    Because it doesn't equal 1, maybe?

    >> In fact, it will print "OneZeroHello World".

    It'll actually skip the first case label, so the output would be "ZeroHello World".
    Code:
    #include <cmath>
    #include <complex>
    bool euler_flip(bool value)
    {
        return std::pow
        (
            std::complex<float>(std::exp(1.0)), 
            std::complex<float>(0, 1) 
            * std::complex<float>(std::atan(1.0)
            *(1 << (value + 2)))
        ).real() < 0;
    }

  4. #4
    ATH0 quzah's Avatar
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    Why would you expect it to? Fall-through doesn't mean it always hits every case label. It means if it matches one, and there's no fall-through protection (break), it will do everything that comes after it until it finds a reason to stop.


    Quzah.
    Hope is the first step on the road to disappointment.

  5. #5
    and the hat of sweating
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    When it falls through, it falls down, not up.
    Set x=1 and it'll print them all.
    "I am probably the laziest programmer on the planet, a fact with which anyone who has ever seen my code will agree." - esbo, 11/15/2008

    "the internet is a scary place to be thats why i dont use it much." - billet, 03/17/2010

  6. #6
    and the Hat of Guessing tabstop's Avatar
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    Quote Originally Posted by Sebastiani View Post
    Because it doesn't equal 1, maybe?
    Ha! That will (okay, should) teach me to read the code and not the question.

  7. #7
    Registered User linuxdude's Avatar
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    Quote Originally Posted by tabstop View Post
    Ha! That will (okay, should) teach me to read the code and not the question.
    lol. Do you know about the break statement Jasper?

  8. #8
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    I think the problem was to illustrate the out of order sequence of the case statements and how it will effect the outcome. I think he was suppose to test the code and learn. Personly instead of changing x to equal 1 I would simply change the case 1: to case 0: and case 0: to case 1: keeping the outputs in the same order. If the point was to get all three to print. :P

    Like :
    Code:
    main()
    {
    
     int x=0;
     switch(x)
     {
      case 0: printf( "One" );
      case 1: printf( "Zero" );
      case 2: printf( "Hello World" );
     }
     }

  9. #9
    Banned ಠ_ಠ's Avatar
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    Quote Originally Posted by strickyc View Post
    I think the problem was to illustrate the out of order sequence of the case statements and how it will effect the outcome. I think he was suppose to test the code and learn. Personly instead of changing x to equal 1 I would simply change the case 1: to case 0: and case 0: to case 1: keeping the outputs in the same order. If the point was to get all three to print. :P

    Like :
    Code:
    main()
    {
    
     int x=0;
     switch(x)
     {
      case 0: printf( "One" );
      case 1: printf( "Zero" );
      case 2: printf( "Hello World" );
     }
     }
    You'd rather change 2 things than 1?
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  10. #10
    ATH0 quzah's Avatar
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    case 0: printf( "One" );
    case 1: printf( "Zero" );
    I hope all of your code doesn't end up as "clear" as this.


    Quzah.
    Hope is the first step on the road to disappointment.

  11. #11
    Registered User
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    Jus a nitpick, but you have things backwards - case 0 is printing 'one' and case 1 is printing 'zero' in the "fixed" code.

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