[Previous]
[Contents]
[Next]

isupper()

test for any uppercase letter

Synopsis:

#include <ctype.h>
int isupper( int c );

Description:

The isupper() function tests for any uppercase letter A through Z.

Returns:

A nonzero value when the argument is an uppercase letter, otherwise zero.

Examples:

#include <stdio.h>
#include <ctype.h>

char chars[] = {A, a, z, Z};

#define SIZE sizeof( chars ) / sizeof( char )

void main()
  {
    int   i;

    for( i = 0; i < SIZE; i++ ) {
      printf( "Char %c is %san uppercase character\n",
        chars[i],
        ( isupper( chars[i] ) ) ? "" : "not " );
    }
  }

produces the output

Char A is an uppercase character
Char a is not an uppercase character
Char z is not an uppercase character
Char Z is an uppercase character

Classification:

ANSI

Safety:
Interrupt handler Yes
Signal handler Yes
Thread Yes

See also:

isalnum(), isalpha(), iscntrl(), isdigit(), isgraph(), islower(), isprint(), ispunct(), isspace(), isxdigit(), tolower(), toupper()


[Previous]
[Contents]
[Next]