C++ iswcntrl()

The iswcntrl() function is defined in <cwctype> header file.

iswcntrl() prototype

int iswcntrl(wint_t ch);

The iswcntrl() function checks if ch is a control character or not. By default, the characters with the codes from 0x00 to 0x1F and 0x7F are considered control characters.

iswcntrl() Parameters

• ch: The wide character to check.

iswcntrl() Return value

• The iswcntrl() function returns non zero value if ch is a control character.
• It returns zero if ch is not a control character.

Example: How iswcntrl() function works?

#include <cwctype>
#include <iostream>
using namespace std;

int main()
{
	wchar_t ch1 = L'\u000c';// unicode for form feed
	wchar_t ch2 = L'\u03a3';// unicode for Σ
	
	cout << hex << showbase << boolalpha << "iswcntrl(" << (wint_t)ch1 << ") returned " << (bool)iswcntrl(ch1) << endl;
	cout << hex << showbase << boolalpha << "iswcntrl(" << (wint_t)ch2 << ") returned " << (bool)iswcntrl(ch2) << endl;

	return 0;
}

When you run the program, the output will be:

iswcntrl(0xc) returned true
iswcntrl(0x3a3) returned false