C++ Operator Precedence

http://en.cppreference.com/w/cpp/language/operator_precedence

C++ Operator Precedence

The following table lists the precedence and associativity of C++ operators. Operators are listed top to bottom, in descending precedence.

PrecedenceOperatorDescriptionAssociativity
1 :: Scope resolution Left-to-right
2 ++ -- Suffix/postfix increment and decrement
() Function call
[] Array subscripting
. Element selection by reference
-> Element selection through pointer
typeid() Run-time type information (see typeid)
const_cast Type cast (see const_cast)
dynamic_cast Type cast (see dynamic_cast)
reinterpret_cast Type cast (see reinterpret_cast)
static_cast Type cast (see static_cast)
3 ++ -- Prefix increment and decrement Right-to-left
+ - Unary plus and minus
! ~ Logical NOT and bitwise NOT
(type) Type cast
* Indirection (dereference)
& Address-of
sizeof Size-of
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 Right-to-Left
16 = 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
17 throw Throw operator (exceptions throwing)
18 , Comma Left-to-right

When parsing an expression, an operator which is listed on some row will be bound tighter (as if by parentheses) to its arguments than any operator that is listed on a row further below it. For example, the expression std::cout<<a&b is parsed as (std::cout<<a)&b and not std::cout<<(a&b).

Operators that are in the same cell (there may be several rows of operators listed in a cell) are evaluated with the same precedence, in the given direction. For example, the expressions *p++ and a=b=c are parsed as *(p++) and a=(b=c), and not as (*p)++ or (a=b)=c because of right-to-left associativity.

An operator's precedence is unaffected by overloading.

posted on 2012-02-15 16:42  Richard.FreeBSD  阅读(295)  评论(0编辑  收藏  举报

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