The wcstoimax and wcstoumax functions in C/C++ function similarly to the strtoimax and strtoumax functions in C++, with the distinction that they specifically handle the conversion of wide strings (wstring) to integral numbers in a specified base. These functions are declared in the cinttypes header file.
Header file:
#include <inttypes.h>
wcstoimax method:
wcstoimax stands for "Wide Character String to Maximum Integer" and is used to convert a wide-character string into a signed integer of type intmax_t with the maximum width. This function supports conversion of wide-character strings in different bases such as decimal, hexadecimal, and octal, based on the format of the provided input text.
Syntax:
It has the following syntax:
#include <inttypes.h>
intmax_t wcstoimax(const wchar_t *npt, wchar_t **endpt, int bases);
Parameters:
The npt parameter represents the numerical value that needs to be converted into a wide-character string.
endpt: A reference to wide characters storing the location indicating the initial erroneous character of the function within the provided input string.
The base of a number system refers to the numerical radix used, such as 10 for decimal, 16 for hexadecimal, and other variations.
Return Value:
The function provides dual outputs in the following manner:
- In cases where a valid conversion exists, the function yields the resulting integer value.
- Should a valid conversion not be achievable, the function outputs a value of zero (0).
Example:
// Program to implement the
// wstoimax() function in C++
#include <bits/stdc++.h>
using namespace std;
// Driver code
int main()
{
wstring st = L"Programming";
intmax_t value = wcstoimax(st.c_str(), nullptr, 36);
wcout << st << " in base 36 is " << value << " in base 10\n\n";
wchar_t* endp;
value = wcstoimax(st.c_str(), &endp, 30);
// Because 'w' is not in base 30, string
// above this cannot be transformed.
wcout << "The given input String is = " << st << endl;
wcout << "The Number with the base 30 in the given string " << value << " in base 10" << endl;
//statement for the display of the next string
wcout << "the end of the string points to " << endp << endl;
return 0;
}
Output:
Programming in base 36 is 94215099711813100 in base 10
The given input String is = Programming
The Number with the base 30 in the given string 15309807264430906 in base 10
the end of the string points to
wcstoumax method:
The wcstoumax function converts the wide-character string npt to the unsigned integer type uintmaxt. The base input ranges from 0 to between 2 and 36. This function behaves similarly to wcstoul and wcstoull, with the key difference being that it outputs a value of type uintmaxt.
Syntax:
It has the following syntax:
#include <inttypes.h>
uintmax_t wcstoumax(const wchar_t *npt, wchar_t **endpt, int bases);
Parameters:
npt: The numerical value to be converted into a wide-character string.
endpt: It is a pointer that holds wide characters indicating the location of the initial incorrect character in the provided input string within the function.
bases: The base of a number system (e.g., 10 for decimal, 16 for hexadecimal, etc.).
Example:
// Program to implement the
// wcstoumax() function in C++
#include <bits/stdc++.h>
using namespace std;
// Driver code
int main()
{
int baseValue = 10;
// L is the literal value to represent the wide string
wstring st = L"123abc";
wchar_t* endp;
uintmax_t number;
number = wcstoumax(st.c_str(), &endp, baseValue);
wcout << "The given input String = " << st << endl;
wcout << "The Value stored in the number is: " << number<< endl;
if (*endp) {
wcout << "The end of the string points to " << endp << endl
<< endl;
}
else {
wcout << "Null pointer" << endl
<< endl;
}
//Because there is no number character in this case, the method returns 0.
baseValue = 10;
wstring st2 = L"abcdeed";
number = wcstoumax(st2.c_str(), &endp, baseValue);
wcout << "The given input String = " << st2 << endl;
wcout << "The Value stored in the number is: " << number<< endl;
if (*endp) {
wcout << "The end of the string points to " << endp << endl
<< endl;
}
else {
wcout << "Null pointer" << endl
<< endl;
}
return 0;
}
Output:
The given input String = 123abc
The Value stored in the number is: 123
The end of the string points to abc
The given input String = abcdeed
The Value stored in the number is: 0
The end of the string points to abcdeed
Uses of wcstoimax and wcstoumax function:
- When dealing with maximum-width signed integers in multiple bases, use wcstoimax to convert wide-character sequences representing numbers to intmax_t type.
- When dealing with maximum-width unsigned integers in multiple bases, use wcstoumax to convert wide-character strings denoting integers to uintmax_t type.
