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warning: deprecated conversion from string constant to ‘char*

This is a discussion on warning: deprecated conversion from string constant to ‘char* within the C Programming forums, part of the General Programming Boards category; Code: char * seq = "1234567890"; Why is this happening? This seems like a very normal thing to do....

  1. #1
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    warning: deprecated conversion from string constant to ‘char*

    Code:
    char * seq  = "1234567890";
    Why is this happening? This seems like a very normal thing to do.

  2. #2
    and the Hat of Guessing tabstop's Avatar
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    Should be const char *.

  3. #3
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    That works. Also, I found char seq[] = "1234567890"; worked too.

  4. #4
    Registered User TheBigH's Avatar
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    The reason is that "1234567890" creates a string constant somewhere in memory. It cannot be modified in any way. So any pointer to it should explicitly be said to be a pointer to a constant.

    char seq[] = "1234567890" is a bit of an abuse of notation; it is shorthand for
    Code:
    char seq[] = { '1', '2', '3', '4', '5', '6', '7', '8', '9', '0' }
    which is a perfectly legitimate array initialization.
    Code:
    while(!asleep) {
       sheep++;
    }

  5. #5
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    i want to say ,my program is all normal

  6. #6
    C++ Witch laserlight's Avatar
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    Quote Originally Posted by TheBigH
    char seq[] = "1234567890" is a bit of an abuse of notation; it is shorthand for
    Actually, it is shorthand for:
    Code:
    char seq[] = {'1', '2', '3', '4', '5', '6', '7', '8', '9', '0' '\0'}
    I don't see why it would be "a bit of an abuse of notation".
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    yeah ! #6 is right !

  8. #8
    Registered User TheBigH's Avatar
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    Quote Originally Posted by laserlight View Post
    Actually, it is shorthand for:
    Code:
    char seq[] = {'1', '2', '3', '4', '5', '6', '7', '8', '9', '0' '\0'}
    I don't see why it would be "a bit of an abuse of notation".
    Whoops, you're right. I forgot the '\0'.

    I call it a bit of an abuse of notation because AFAIK that is the only time in C where something inside quotation marks is handled as shorthand for something else.
    Code:
    while(!asleep) {
       sheep++;
    }

  9. #9
    Algorithm Dissector iMalc's Avatar
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    IMHO it is not the least bit abuse.
    It's no different to me than using a += b; instead of a = a + b; is. It's just two different ways of representing the same thing.
    In fact the shorter, more concise option is definitely the preferred option.
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