wcstoimax() and wcstoumax() function in C/C++

The wcstoimax() and wcstoumax() function in C/C++ works exactly same as strtoimax() and strtoumax() function in C++ but are used to convert the contents of a wide string (wstring) as an integral number of the specified base. This function is defined in cinttypes header file.

Syntax:

uintmax_t wcstoumax(const wchar* wstr, wchar** end, int base);
intmax_t wcstoimax(const wchar* wstr, wchar** end, int base);

Parameters: The function accepts three mandatory parameters as described below:

• wstr: specifies a wide string consist of an integral number.
• end: specifies a reference to object of type wchar*. The value of end is set by the function to the next character in wstr after the last valid numeric character. This parameter can also be a null pointer, in case if it is not used.
• base: specifies the numerical base (radix) that determines the valid characters and their interpretation in the string

Return Type: The function returns two values as follows:

• If valid conversion occur then the function returns the converted integral number as integer value.
• If no valid conversion could be performed then, a zero value is returned (0)

Below programs illustrate the above function:
Program 1 :

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

// Driver code
int main()
{
    wstring str = L"geeksforgeeks";

    intmax_t val = wcstoimax(str.c_str(), nullptr, 36);

    wcout << str << " in base 36 is " << val << " in base 10\n\n";

    wchar_t* end;

    val = wcstoimax(str.c_str(), &end, 30);

    // 'w' does not lies in base 30 so string
    // beyond this cannot be converted
    wcout << "Given String = " << str << endl;

    wcout << "Number with base 30 in string " << val << " in base 10" << endl;

    wcout << "End String points to " << end << endl;

    return 0;
}

Output:

geeksforgeeks in base 36 is 9223372036854775807 in base 10

Given String = geeksforgeeks
Number with base 30 in string 8759741037015451228 in base 10
End String points to

Program 2 :

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

// Driver code
int main()
{
    int base = 10;

    // L is a wide string literal
    wstring str = L"12345abcd";
    wchar_t* end;
    uintmax_t num;

    num = wcstoumax(str.c_str(), &end, base);

    wcout << "Given String = " << str << endl;

    wcout << "Value stored in num " << num << endl;

    if (*end) {
        wcout << "End string points to " << end << endl
              << endl;
    }
    else {
        wcout << "Null pointer" << endl
              << endl;
    }

    // in this case no numeric character is there
    // so the function returns 0
    base = 10;

    wstring str2 = L"abcd";

    wcout << "Given String = " << str2 << endl;

    num = wcstoumax(str2.c_str(), &end, base);

    wcout << "Number with base 10 in string " << num << endl;
    if (*end) {
        wcout << "End String points to " << end;
    }
    else {
        wcout << "Null pointer";
    }
    return 0;
}

Output:

Given String = 12345abcd
Value stored in num 12345
End string points to abcd

Given String = abcd
Number with base 10 in string 0
End String points to abcd