C toupper() function

C toupper(int c)

The toupper() function is used to translate lowercase characters to uppercase characters. The function is defined in the ctype.h header file.

Syntax:

int toupper(int ch);

toupper() Parameters:

Return value from toupper()

• Upon successful completion, toupper() returns the uppercase letter corresponding to the argument passed; otherwise returns the argument unchanged.

Example: C toupper() function

#include <stdio.h>
#include <ctype.h>
int main() {
    char ch;
     printf("Convert lower case to upper case:\n");
    ch = 'M';
    printf("%c -> %c", ch, toupper(ch));

    ch = 'k';
    printf("\n%c -> %c", ch, toupper(ch));
    ch = 'y';
    printf("\n%c -> %c", ch, toupper(ch));
    ch = 'w';
    printf("\n%c -> %c", ch, toupper(ch));
    return 0;
}

Output:

Convert lower case to upper case:
M -> M
k -> K
y -> Y
w -> W

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