isupper


function
<cctype>
int isupper ( int c );

Check if character is uppercase letter

Checks if parameter c is an uppercase alphabetic letter.

Notice that what is considered a letter may depend on the locale being used; In the default C locale, an uppercase letter is any of: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z.

For a detailed chart on what the different ctype functions return for each character of the standard ANSII character set, see the reference for the <cctype> header.

In C++, a locale-specific template version of this function (isupper) exists in header <locale>.

Parameters

c
Character to be checked, casted to an int, or EOF.


Return Value

A value different from zero (i.e., true) if indeed c is an uppercase alphabetic letter. Zero (i.e., false) otherwise.

Example

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/* isupper example */
#include <stdio.h>
#include <ctype.h>
int main ()
{
  int i=0;
  char str[]="Test String.\n";
  char c;
  while (str[i])
  {
    c=str[i];
    if (isupper(c)) c=tolower(c);
    putchar (c);
    i++;
  }
  return 0;
}


Output:
test string.


See also