C/C++速查表

A sorted C/C++ cheat sheet, regularly organized and placed here for convenient reference.

C++ Operator Precedence

Associativity	Operator	Function	Usage
Left	::	Global Scope	::name
Left	::	Class Scope	class::name
Left	::	Namespace Scope	namespace::name
Left	.	Member Access	object.member
Left	->	Member Access	pointer->member
Left	[]	Subscript	expr[expr]
Left	()	Function Call	name(expr_list)
Left	()	Type Constructor	type(expr_list)
Right	++	Post-increment	lvalue++
Right	–	Post-decrement	lvalue–
Right	typeid	Type ID	typeid(type)
Right	typeid	Runtime Type ID	typeid(expr)
Right	explicit cast	Type Conversion	cast_name(expr)
Right	++	Pre-increment	++lvalue
Right	–	Pre-decrement	–lvalue
Right	~	Bitwise NOT	~expr
Right	!	Logical NOT	!expr
Right	-	Unary Negation	-expr
Right	+	Unary Positive	+expr
Right	*	Dereference	*expr
Right	&	Address-of	&lvalue
Right	()	Type Conversion	(type)expr
Right	sizeof	Size of Object	sizeof expr
Right	sizeof	Size of Type	sizeof(expr)
Right	sizeof	Size of Parameter Pack	sizeof…(name)
Right	new	Create Object	new type
Right	new[]	Create Array	new type[size]
Right	delete	Release Object	delete expr
Right	delete[]	Release Array	delete[] expr
Right	noexcept	Can throw exception	noexcept(expr)
Left	->*	Pointer to Member Access	ptr->*ptr_to_member
Left	.*	Pointer to Member Access	obj.*ptr_to_member
Left	*	Multiplication	expr*expr
Left	/	Division	expr/expr
Left	%	Modulo (Remainder)	expr%expr
Left	+	Addition	expr+expr
Left	-	Subtraction	expr-expr
Left	<<	Left Shift	expr<<expr
Left	>>	Right Shift	expr>>expr
Left	<	Less than	expr<expr
Left	<=	Less than or Equal	expr<=expr
Left	>	Greater than	expr>expr
Left	>=	Greater than or Equal	expr>=expr
Left	==	Equality	expr==expr
Left	!=	Inequality	expr!=expr
Left	&	Bitwise AND	expr&expr
Left	^	Bitwise XOR	expr^expr
Left	¦	Bitwise OR	expr ¦ expr
Left	&&	Logical AND	expr && expr
Left	¦¦	Logical OR	expr ¦¦ expr
Right	?:	Conditional (Ternary Operator)	expr?expr:expr
Right	=	Assignment	lvalue=expr
Right	*/,/=,%=,+=,-=,<<=,>>=,&=, ¦=,^=	Compound Assignment	lvalue+=expr etc.
Right	throw	Throw Exception	throw expr
Right	,	Comma Operator	expr,expr

C++ Keywords

alignas (since C++11)	else	requires (concepts TS)
alignof (since C++11)	enum	return
and	explicit	short
and_eq	export(1)	signed
asm	extern	sizeof
auto(1)	false	static
bitand	float	static_assert (since C++11)
bitor	for	static_cast
bool	friend	struct
break	goto	switch
case	if	template
catch	inline	this
char	int	thread_local (since C++11)
char16_t (since C++11)	long	throw
char32_t (since C++11)	mutable	true
class	namespace	try
compl	new	typedef
concept (concepts TS)	noexcept (since C++11)	typeid
const	not	typename
constexpr (since C++11)	not_eq	union
const_cast	nullptr (since C++11)	unsigned
continue	operator	using(1)
decltype (since C++11)	or	virtual
default(1)	or_eq	void
delete(1)	private	volatile
do	protected	wchar_t
double	public	while
dynamic_cast	register	xor
reinterpret_cast	xor_eq

Conversion Specifiers in C

Conversion	Output Specification
%a	Floating-point number, hexadecimal digits and p-notation (C99/C11).
%A	Floating-point number, hexadecimal digits and P-notation (C99/C11). Exploring and Exploiting printf() and scanf()
%c	Single character.
%d	Signed decimal integer.
%e	Floating-point number, e-notation.
%E	Floating-point number, e-notation.
%f	Floating-point number, decimal notation.
%g	Use %f or %e , depending on the value. The %e style is used if the exponent is less than −4 or greater than or equal to the precision.
%G	Use %f or %E , depending on the value. The %E style is used if the exponent is less than −4 or greater than or equal to the precision.
%i	Signed decimal integer (same as
%o	Unsigned octal integer.
%p	A pointer.
%s	Character string.
%u	Unsigned decimal integer.
%x	Unsigned hexadecimal integer, using hex digits 0f .
%X	Unsigned hexadecimal integer, using hex digits 0F .
%%	Prints a percent sign.