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string functions

krampovpi asked
Medium Priority
Last Modified: 2010-04-15
i want to write a function void shift(char *) that looks at the first character of its argument and converts the other characters, to be the same case, that is, if the first character is uppercase, it shifts the rest to uppercase; if the first character is lowercase, it shifts the rest to lowercase, and otherwise, it does nothing.
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Do you have a question about doing that?
the functions isupper, islower, toupper and tolower may be of interest.
Kent OlsenData Warehouse / Database Architect


void SameCase (char *string)
  if (isupper (string)
    // Convert the entire string to upper case
  else if (islower (string))
    // convert the entire string to lower case

That's about it.

That's not right...  string is a pointer to the first character position,
therefore you need to dereference it to access the first character position of the string.

void SameCase (char *string)
   if (!isascii(*string)) {

  if (isupper (*string)
    // Convert the entire string to upper case
  else if (islower (*string))
    // convert the entire string to lower case

You can use  toupper/tolower to get the lowercase/uppercase version of any character in the string.

Be sure to check isascii() first;  the islower/isupper/toupper/tolower and many other character functions
require that the argument either be EOF or a valid  unsigned char.

Meaning if the unsigned value of the character is 128 or higher, or the signed value is -1 or less and not EOF,
you need to either not call isupper/islower, OR you need to cast to an unsigned char.

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