function

toupper

<cctype> 
int toupper ( int c );
Convert lowercase letter to uppercase
Converts parameter c to its uppercase equivalent if c is a lowercase letter and has an uppercase equivalent. If no such conversion is possible, the value returned is c unchanged.

Notice that what is considered a letter may depend on the locale being used; In the default C locale, a lowercase 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, which translate respectively to: 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.

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

Parameters

c
Lowercase letter character to be converted, casted to an int, or EOF.

Return Value

The uppercase equivalent to c, if such value exists, or c (unchanged) otherwise. The value is returned as an int value that can be implicitly casted to char.

Example

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/* toupper 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];
    putchar (toupper(c));
    i++;
  }
  return 0;
}


Output:
TEST STRING.

See also

tolower
Convert uppercase letter to lowercase (function)
islower
Check if character is lowercase letter (function)
isupper
Check if character is uppercase letter (function)
isalpha
Check if character is alphabetic (function)