int isupper ( int c );

<cctype>

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.

Parameters

c

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

Return Value

Example

/* 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