wcstoll() function in C/C++

The wcstoll() function in C/C++ converts a wide-character string to a long long integer. It sets the pointer to point the first character after the last character.

Syntax :

long long wcstoll( const wchar_t* str, wchar_t** str_end, int base )

Parameter: The function accepts three mandatory parameters which are described as below:

• str: it specifies a wide string starting with the integral number.
• str_end: the str_end value is set by the function to the next char, after the last valid character, if there any, or it will point to NULL.
• base: specifies the base, the values of Base can be of {0, 2, 3, …, 35, 36}.

Return value: The function returns the converted long long integer. It returns 0, it the character points to NULL.

Below programs illustrate the above function:

Program 1 :

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

int main()
{
    // wide-character type array string starting
    // with integral 'L'
    wchar_t string1[] = L"888geekforgeeks";
    wchar_t string2[] = L"999gfg";

    // End pointer will point to the characters
    // after integer, according to the base
    wchar_t* End;

    // Initializing base
    int b = 10;
    int value;

    value = wcstoll(string1, &End, b);
    value = wcstoll(string2, &End, b);

    // prints the whole input string
    wcout << "String Value = " << string1 << "\n";
    wcout << "Long Long Int value = " << value << "\n";

    // prints the end string after the integer
    wcout << "End String = " << End << "\n";

    wcout << "String Value = " << string2 << "\n";
    wcout << "Long Long Int Value = " << value << "\n";
    wcout << "End String = " << End << "\n";
    return 0;
}

Output:

String Value = 888geekforgeeks
Long Long Int value = 999
End String = gfg
String Value = 999gfg
Long Long Int Value = 999
End String = gfg

Note: The values for bases can be {0, 2, 3, …, 35, 36}. A set of valid digits for base 2 is {0, 1}, for base 3 is {0, 1, 2} and so on. For bases starting from 11 to 36, valid digits include alphabets. The set of valid digits for base 11 is {0, 1, …, 9, A, a}, for base 12 is {0, 1, …, 9, A, a, B, b} and so on.

Program 2 : function with different bases

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

int main()
{
    // End pointer, will point to the characters
    // after integer, according to the base
    wchar_t* End;

    // wide-character type array string
    wchar_t string[] = L"1356geekforgeeks";

    // Prints the long long integer provided with base 5
    wcout << "Long Long Int with base5 = "
    << wcstoll(string, &End, 5) << "\n";

    wcout << "End String = " << End << "\n";

    // Prints the long long integer provided with base 12
    wcout << "Long Long Int with base12 = "
    << wcstoll(string, &End, 12) << "\n";

    wcout << "End String = " << End << "\n";

    // Prints the long long integer provided with base 36
    wcout << "Long Long Int with base36 = "
    << wcstoll(string, &End, 36) << "\n";

    wcout << "End String = " << End << "\n";

    return 0;
}

Output:

Long Long Int with base5 = 8
End String = 56geekforgeeks
Long Long Int with base12 = 2226
End String = geekforgeeks
Long Long Int with base36 = 9223372036854775807
End String =