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# C++ Operator Precedence

From cppreference.com
< cpp‎ | language

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

1. ↑ The operand of `sizeof` can't be a C-style type cast: the expression `sizeof (int) * p` is unambiguously interpreted as `(sizeof(int)) * p`, but not `sizeof((int)*p)`.
2. ↑ The expression in the middle of the conditional operator (between `?` and `:`) is parsed as if parenthesized: its precedence relative to `?:` is ignored.

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 expressions std::cout<<a&b and *p++ are parsed as (std::cout<<a)&b and *(p++), and not as std::cout<<(a&b) or (*p)++.

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 expression a=b=c is parsed as a=(b=c), and not as (a=b)=c because of right-to-left associativity.

Operator precedence is unaffected by operator overloading.

### [edit] Notes

Precedence and associativity are independent from order of evaluation.

The standard itself doesn't specify precedence levels. They are derived from the grammar.

`const_cast`, `static_cast`, `dynamic_cast`, `reinterpret_cast`, `typeid`, `sizeof...`, `noexcept` and `alignof` are not included since they are never ambiguous.

Some of the operators have alternate spellings (e.g., and for `&&`, or for `||`, not for `!`, etc.).

Relative precedence of the conditional and assignment operators differs between C and C++: in C, assignment is not allowed on the right hand side of a conditional operator, so e = a < d ? a++ : a = d cannot be parsed. Many C compilers use a modified grammar where `?:` has higher precedence than `=`, which parses that as e = ( ((a < d) ? (a++) : a) = d ) (which then fails to compile because `?:` is never lvalue in C and `=` requires lvalue on the left). In C++, `?:` and `=` have equal precedence and group right-to-left, so that e = a < d ? a++ : a = d parses as e = ((a < d) ? (a++) : (a = d)).

### [edit] See also

Common operators
assignment | increment decrement | arithmetic | logical | comparison | member access | other
a = b a += b a -= b a *= b a /= b a %= b a &= b a |= b a ^= b a <<= b a >>= b | ++a --a a++ a-- | +a -a a + b a - b a * b a / b a % b ~a a & b a | b a ^ b a << b a >> b | !a a && b a || b | a == b a != b a < b a > b a <= b a >= b | a[b] *a &a a->b a.b a->*b a.*b | a(...) a, b (type) a ? :
Special operators
`static_cast` converts one type to another compatible type `dynamic_cast` converts virtual base class to derived class `const_cast` converts type to compatible type with different cv qualifiers `reinterpret_cast` converts type to incompatible type `new` allocates memory `delete` deallocates memory `sizeof` queries the size of a type `sizeof...` queries the size of a parameter pack (since C++11) `typeid` queries the type information of a type `noexcept` checks if an expression can throw an exception (since C++11) `alignof` queries alignment requirements of a type (since C++11)

C documentation for C operator precedence

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