运算符优先级

                  （高）

算数             

关系             

&&和||           

赋值              （低）

相关资料：C++ Operator Precedence

Precedence	Operator	Description	Associativity
1	::	Scope resolution	Left-to-right
2	++   --	Suffix/postfix increment and decrement
	type() type{}	Function-style type cast
	()	Function call
	[]	Array subscripting
	.	Element selection by reference
	->	Element selection through pointer
3	++   --	Prefix increment and decrement	Right-to-left
	+   -	Unary plus and minus
	!   ~	Logical NOT and bitwise NOT
	(type)	C-style type cast
	*	Indirection (dereference)
	&	Address-of
	sizeof	Size-of[note 1]
	new, new[]	Dynamic memory allocation
	delete, delete[]	Dynamic memory deallocation
4	.*   ->*	Pointer to member	Left-to-right
5	*   /   %	Multiplication, division, and remainder
6	+   -	Addition and subtraction
7	<<   >>	Bitwise left shift and right shift
8	<   <=	For relational operators < and ≤ respectively
	>   >=	For relational operators > and ≥ respectively
9	==   !=	For relational = and ≠ respectively
10	&	Bitwise AND
11	^	Bitwise XOR (exclusive or)
12	|	Bitwise OR (inclusive or)
13	&&	Logical AND
14	||	Logical OR
15	?:	Ternary conditional[note 2]	Right-to-left
	=	Direct assignment (provided by default for C++ classes)
	+=   -=	Assignment by sum and difference
	*=   /=   %=	Assignment by product, quotient, and remainder
	<<=   >>=	Assignment by bitwise left shift and right shift
	&=   ^=   |=	Assignment by bitwise AND, XOR, and OR
16	throw	Throw operator (for exceptions)
17	,	Comma	Left-to-right