C++ Basic Tutorial

C++ Flow Control (流程控制)

C++ Function (函数)

C++ Array & String (数组 & 字符串)

C++ Data Structure (数据结构)

C++ Class & Object (类 & 对象)

C++ Pointer (指针)

C++ Inheritance (继承)

C++ STL Tutorial (STL教程)

C++ Reference Manual

C++ <cmath>

C++ Vector (Vector)C++ Numbers

c++ Keywords and Identifiers

In this tutorial, we will learn about keywords (C ++Reserved keywords in programming, which are part of the syntax). We will also learn about identifiers and how to name them.

C++ Keywords

Keywords arePredefinedwords have special meanings to the compiler. For example,

Example

int money;

Here, int is a keyword indicating that money is a variable of integer type.

This is all C ++List of keywords. (From C ++ 17Start)

alignas	decltype	namespace	struct
alignof	default	new	switch
and	delete	noexcept	template
and_eq	do	not	this
asm	double	not_eq	thread_local
auto	dynamic_cast	nullptr	throw
bitand	else	operator	true
bitor	enum	or	try
bool	explicit	or_eq	typedef
break	export	private	typeid
case	extern	protected	typename
catch	false	public	union
char	float	register	unsigned
char16_t	for	reinterpret_cast	using
char32_t	friend	return	virtual
class	goto	short	void
compl	if	signed	volatile
const	inline	sizeof	wchar_t
constexpr	int	static	while
const_cast	long	static_assert	xor
continue	mutable	static_cast	xor_eq

Note:Due to C ++is case-sensitive language, so all keywords must be written in lowercase letters.

C++ Identifier

Identifiers are unique names given by programmers to variables, classes, functions, or other entities. For example,

Example

int money;
double accountBalance;

Here, money and accountBalance are identifiers.

Identifier naming rules

Identifiers can consist of letters, digits, and underscore characters.
There is no limit to the length of the name.
It must start with a letter or underscore.
Case sensitive.
We cannot use keywords as identifiers.

If we follow the above rules, we can choose any name as an identifier. However, we should provide meaningful names for meaningful identifiers.

Example of good and bad identifiers

Illegal identifier	Invalid identifier	Good identifier
Total points	T_points	totalPoint
1list	list_1	list1
float	n_float	floatNumber

C++ Vector (Vector)C++ Numbers