toupper() function in C
The toupper() function is used to convert lowercase alphabet to uppercase. i.e. If the character passed is a lowercase alphabet then the toupper() function converts a lowercase alphabet to an uppercase alphabet. It is defined in the ctype.h header file.
Syntax:
int toupper(int ch);
Parameter: It accepts a single parameter:
- ch: This represents the character to be converted to uppercase.
Returns: This function returns the uppercase character corresponding to the ch.
Below programs illustrate the toupper() function in C:
Example 1:-
c
// C program to demonstrate// example of toupper() function.#include <ctype.h>#include <stdio.h>int main(){ char ch; ch = 'g'; printf("%c in uppercase is represented as %c", ch, toupper(ch)); return 0;} |
Output:
g in uppercase is represented as G
Example 2:-
C
// C program to demonstrate// example of toupper() function.#include <ctype.h>#include <stdio.h>int main(){ int j = 0; char str[] = "geekforgeeks\n"; char ch; while (str[j]) { ch = str[j]; putchar(toupper(ch)); j++; } return 0;} |
Output:
GEEKFORGEEKS
Note:
If the character passed in the toupper() is any of these three
1. uppercase character
2. special symbol
3. digit
toupper() will return the character as it is.
Example :
C
// C program to demonstrate// example of toupper() function.#include <ctype.h>#include <stdio.h>int main(){ int j = 0; char str[] = "GeEks@123\n"; char ch; while (str[j]) { ch = str[j]; putchar(toupper(ch)); j++; } return 0;}// code is contributed by codersaty |
Output:
GEEKS@123
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