Identifiers in C++ Programming

Definition of Identifiers

An identifier is a programmer-defined name that represents some element of a program. Variable names are examples of identifiers. You may choose your own variable names in C++, as long as you do not use any of the C++ key words.

C++ Key Words
and	continue	goto	public	try
and_eq	default	if	register	typedef
asm	delete	inline	reinterpret_cast	Typeid
auto	do	int	return	typename
bitand	double	long	short	union
bitor	dynamic_cast	mutable	signed	unsigned
bool	else	namespace	sizeof	using
break	enum	new	static	virtual
case	explicit	not	static_cast	void
catch	export	not_eq	struct	volatile
char	extern	operator	switch	wchar_t
class	false	or	template	while
compl	float	or_eq	this	xor
const	for	private	throw	xor_eq
Const_cast	friend	protected	true

Legal Identifiers

Regardless of which style you adopt, be consistent and make your variable names as sensible as possible. Here are some specific rules that must be followed with all C++ identifiers.

The first character must be one of the letters a through z, A through Z, or an underscore character (_).
After the first character you may use the letters a through z or A through Z, the digits 0 through 9, or underscores.
Uppercase and lowercase characters are distinct. This means ItemsOrdered is not the same as itemsordered.

Variable Name	Legal or Illegal
dayOfWeek	Legal.
3dGraph	Illegal. Variable names cannot begin with a digit.
_employee_num	Legal.
June1997	Legal.
Mixture#3	Illegal. Variable names may only use letters, digits, and underscores.

Ads Right