Thread: Manipulating Strings? (tolower, toupper, ucfirst)

  1. #1
    Registered User
    Join Date
    Apr 2006
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    11

    Manipulating Strings? (tolower, toupper, ucfirst)

    Hello all!

    I'm interested in creating a function that will take in an array and, using pointers, change that array to all lowercase. The process will be replicated in 2 other functions to change all of the array to uppercase letters or just the first letter of each word capitalized.

    What I have is as follows:
    Code:
    int strtolower(char theString[]){
    	int theLength = strlen(theString);
    	for (i=0;i<theLength;i++)
    		theString[i] = toupper(theString[i]);
    	
    	return 1;
    }
    However, my program stops unexpectedly when calling the function using:
    Code:
    char someArray[50][50][50];
    
    strtolower(someArray[0][0]);

    Any suggestions as to why my program is not performing as expected? Thanks for any help you can give!

  2. #2
    Registered User
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    Sep 2007
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    1,012
    First off, you're not allowed to name your function strtolower (names beginning with str are reserved). But that's probably not your problem.

    someArray contains no string. It's just a declaration of an array, but it contains junk (unless it's global). You need to copy a string somewhere into it first.

  3. #3
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    Apr 2006
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    thanks for the insight about str,i I wasn't aware of that!

    However, the code I presented was just an example of the usage. In my actual usage there are values in the array. How can I make this work if there aren't values? If there are?

    Thanks for the speedy response!

  4. #4
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    Feb 2010
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    Well then to get help you should post more code.

  5. #5
    Registered User
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    Apr 2006
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    Ok so the problem isn't in the function then? That's all I needed to know I guess...

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