digit_value

Determines the numeric value of a character as a decimal digit.

If the character is not a decimal digit according to [func@GLib.ascii_isdigit], `-1` is returned.

Differs from [func@GLib.unichar_digit_value] because it takes a char, so there's no worry about sign extension if characters are signed.

Example: Determine the character as a decimal digit:

public static int main (string[] args) {
	// Output: ``'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', ``
	for (int i = 0; i <= 255; i++) {
		if (((char) i).digit_value () >= 0) {
			print ("'%c', ", (char) i);
		}
	}
	print ("\n");
	return 0;
}

valac --pkg glib-2.0 char.digit_value.vala

Parameters:

c	an ASCII character

Returns:

the numerical value of c if it is a decimal digit, `-1` otherwise