The iswdigit() is a built-in function in C++ STL which checks if the given wide character is an decimal digit character or not. It is defined within the cwctype header file of C++. The characters from 0 to 9 i.e.0, 1, 2, 3, 4, 5, 6, 7, 8, 9 are classified as decimal digits.
Syntax:
int iswdigit(ch)
Parameter: The function accepts a single mandatory parameter ch which specifies the wide character which we have to check that if it is a digit or not.
Return Value: The function returns two values as shown below.
- If the ch is a digit, then a non-zero value is returned.
- If it is not then 0 is returned.
Below programs illustrates the above function.
Program 1:
// C++ program to illustrate // iswdigit() function #include <cwctype> #include <iostream> using namespace std;
int main()
{ wchar_t ch1 = '?' ;
wchar_t ch2 = '3' ;
// Function to check if the character
// is a digit or not
if (iswdigit(ch1))
wcout << ch1 << " is a digit " ;
else
wcout << ch1 << " is not a digit " ;
wcout << endl;
if (iswdigit(ch2))
wcout << ch2 << " is a digit " ;
else
wcout << ch2 << " is not a digit " ;
return 0;
} |
Output:
? is not a digit 3 is a digit
Program 2:
// C++ program to illustrate // iswdigit() function #include <cwctype> #include <iostream> using namespace std;
int main()
{ wchar_t ch1 = '1' ;
wchar_t ch2 = 'q' ;
// Function to check if the character
// is a digit or not
if (iswdigit(ch1))
wcout << ch1 << " is a digit " ;
else
wcout << ch1 << " is not a digit " ;
wcout << endl;
if (iswdigit(ch2))
wcout << ch2 << " is a digit " ;
else
wcout << ch2 << " is not a digit " ;
return 0;
} |
Output:
1 is a digit q is not a digit