C++ Operator Precedence - cppreference.com

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

Precedence Operator Description Associativity 1 a::b

Scope resolution

Left-to-right → 2 a++a--Suffix/postfix

increment and decrement

type(a)type{a}

a()

a[]

a.ba->b

3 ++a--aPrefix

increment and decrement

Right-to-left ← +a-aUnary

!a~a

and

(type)a

(dereference) &a

^^a

(since C++26)

(C++20)

–

Dynamic memory allocation

delete

–

delete[]

Dynamic memory deallocation

4 a.*ba->*b

Pointer-to-member

Left-to-right → 5 a*ba/ba%b

Multiplication, division, and remainder

6 a+ba-b

Addition and subtraction

7 a<<ba>>bBitwise

left shift and right shift

8 a<=>b

Three-way comparison operator

(since C++20)9 a<ba<=ba>ba>=bFor

relational operators

< and <= and > and >= respectively 10 a==ba!=bFor

equality operators

= and != respectively 11 a&b

Bitwise AND

12 a^b

Bitwise XOR

(exclusive or) 13 a|b

Bitwise OR

(inclusive or) 14 a&&b

15 a||b

16 a?b:c

Right-to-left ←

(C++20)a=b

(provided by default for C++ classes) a+=ba-=b

Compound assignment

by sum and difference a*=ba/=ba%=b

Compound assignment

by product, quotient, and remainder a<<=ba>>=b

Compound assignment

by bitwise left shift and right shift a&=ba^=ba|=b

Compound assignment

by bitwise AND, XOR, and OR 17 a,b

Comma

Left-to-right →

↑

The operand of sizeof cannot be a C-style type cast: the expression sizeof(int)*p is unambiguously interpreted as (sizeof(int))*p, but not sizeof((int)*p).

↑

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 of the table above with a precedence will be bound tighter (as if by parentheses) to its arguments than any operator that is listed on a row further below it with a lower precedence. 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 have the same precedence are bound to their arguments in the direction of their associativity. 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 of assignment, but a+b-c is parsed (a+b)-c and not a+(b-c) because of left-to-right associativity of addition and subtraction.

Associativity specification is redundant for unary operators and is only shown for completeness: unary prefix operators always associate right-to-left (delete++*p is delete(++(*p))) and unary postfix operators always associate left-to-right (a[1][2]++ is ((a[1])[2])++). Note that the associativity is meaningful for member access operators, even though they are grouped with unary postfix operators: a.b++ is parsed (a.b)++ and not a.(b++).

Operator precedence is unaffected by

operator overloading

. For example, std::cout<<a?b:c; parses as (std::cout<<a)?b:c; because the precedence of arithmetic left shift is higher than the conditional operator.

Notes

Precedence and associativity are compile-time concepts and are independent from

order of evaluation

, which is a runtime concept.

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

and

are not included since they are never ambiguous.

Some of the operators have

alternate spellings

(e.g., and for &&, or for ||, not for !, etc.).

In C, the ternary conditional operator has higher precedence than assignment operators. Therefore, the expression e=a<d?a++:a=d, which is parsed in C++ as e=((a<d)?(a++):(a=d)), will fail to compile in C due to grammatical or semantic constraints in C. See the corresponding C page for details.