strnset() function in C

The strnset() function is a builtin function in C and it sets the first n characters of a string to a given character. If n is greater than the length of string, the length of string is used in place of n.

Syntax:

char *strnset(const char *str, char ch, int n);

Parameters:

• str: This is the original string in which some character are replaced by a given character.
• ch: ch represents the given character.
• n: n represents the number of character which is replaced by the given character.

Return Value: It returns the modified string obtained after replacing the first characters of the given string str.

Below programs illustrate the strnset() function in C:

Program 1:

// C program to illustrate
// the strnset() function

#include <stdio.h>
#include <string.h>

int main()
{
    char str[] = "GeeksforGeeks";

    printf("Original String: %s\n", str);

    // First 5 character of string str
    // replaced by character '*'
    printf("Modified String: %s\n", strnset(str, '*', 5));

    return 0;
}

Output:

Original String: GeeksforGeeks
Modified String: *****forGeeks

Program 2:

// C program to illustrate
// the strnset() function

#include <stdio.h>
#include <string.h>

int main()
{
    char str[] = "Computer Science";

    printf("Original String: %s\n", str);

    // First 5 character of string str
    // replaced by character '*'
    printf("Modified String: %s\n", strnset(str, '*', 5));

    return 0;
}

Output:

Original String: Computer Science
Modified String: *****ter Science

Note: The strnset() function is not a part of the standard C library and thus might not run on the online compilers.