wcscspn() function in C/C++

The wcscspn() function in C/C++ searches the first occurrence of a wide character of string_2 in the given wide string_1. It returns the number of wide characters before the first occurrence of that wide character . The search includes the terminating null wide characters. Therefore, the function will return the length of string_1 if none of the characters of string_2 are found in string_1.

Syntax:

size_t wcscspn( const wchar_t* string_1, const wchar_t* string_2 )

Parameter : The function accepts two mandatory parameters which are described below:

• string_1 : specifies the string to be searched
• string_2 : specifies the string containing the characters to be searched

Return value: The function returns two value as below:

• It returns the number of wide characters in string_2 before the first occurrence of any wide characters present in string_1.
• length of string_1 is returned if none of the wide characters in string_2 are found in string_1

Below programs illustrate the above function:
Program 1 :

// C++ program to illustrate
// wcscspn() function

#include <bits/stdc++.h>
using namespace std;

int main()
{
    // string to be scanned
    wchar_t string_1[] = L"geeksforgeeks012345";

    // string containing the character to match
    wchar_t string_2[] = L"0123456789";

    // scanning the strings
    int last = wcscspn(string_1, string_2);

    // print the position of a matched character
    if (last > wcslen(string_1))
        wcout << string_1 << L" Didn't match any character";
    else
        wcout << L"Occurrence of a character in -> \n"
              << string_1 << " is at position : " << last;
    return 0;
}

Output:

Occurrence of a character in ->
 geeksforgeeks012345 is at position : 13

Program 2 :

// C++ program to illustrate
// wcscspn() function
#include <bits/stdc++.h>
using namespace std;

int main()
{
    // string to be scanned
    wchar_t string_1[] = L"GFG";

    // string containing the character to match
    wchar_t string_2[] = L"909090909";

    // scanning the strings
    int last = wcscspn(string_1, string_2);

    // print the position of a matched character
    if (last > wcslen(string_1))
        wcout << string_1 << L" does not contain numbers";
    else
        wcout << L"Length of the string -> "
              << string_1 << " is : " << last;
    return 0;
}

Output:

Length of the string -> GFG is : 3