This is a list of operators in the C and C++ programming languages . All listed operators are in C++ and lacking indication otherwise, in C as well. Some tables include a "In C" column that indicates whether an operator is also in C. Note that C does not support operator overloading . When not overloaded, for the operators && , || , and , (the comma operator ), there is a sequence point after the evaluation of the first operand. Most of the operators available in C and C++ are also available in other C-family languages such as C# , D , Java , Perl , and PHP with the same precedence, associativity, and semantics. Many operators specified by a sequence of symbols are commonly referred to by a name that consists of the name of each symbol. For example, += and -= are often called "plus equal(s)" and "minus equal(s)", instead of the more verbose "assignment by addition" and "assignment by subtraction". In the following tables, lower case letters such as a and b represent literal values, object/variable names, or l-values, as appropriate. R , S and T stand for a data type, and K for a class or enumeration type. Some operators have alternative spellings using digraphs and trigraphs or operator synonyms . C and C++ have the same arithmetic operators and all can be overloaded in C++. All relational (comparison) operators can be overloaded in C++. Since C++20 , the inequality operator is automatically generated if operator== is defined and all four relational operators are automatically generated if operator<=> is defined. [ 1 ] C and C++ have the same logical operators and all can be overloaded in C++. Note that overloading logical AND and OR is discouraged, because as overloaded operators they always evaluate both operands instead of providing the normal semantics of short-circuit evaluation . [ 2 ] C and C++ have the same bitwise operators and all can be overloaded in C++. C and C++ have the same assignment operators and all can be overloaded in C++. For the combination operators, a ⊚= b (where ⊚ represents an operation) is equivalent to a = a ⊚ b , except that a is evaluated only once. Member and pointer C++ defines keywords to act as aliases for a number of operators: [ 7 ] Each keyword is a different way to specify an operator and as such can be used instead of the corresponding symbolic variation. For example, (a > 0 and not flag) and (a > 0 && !flag) specify the same behavior. As another example, the bitand keyword may be used to replace not only the bitwise-and operator but also the address-of operator, and it can be used to specify reference types (e.g., int bitand ref = n ). The ISO C specification makes allowance for these keywords as preprocessor macros in the header file iso646.h . For compatibility with C, C++ also provides the header iso646.h , the inclusion of which has no effect. Until C++20, it also provided the corresponding header ciso646 which had no effect as well. Expression evaluation order During expression evaluation, the order in which sub-expressions are evaluated is determined by precedence and associativity . An operator with higher precedence is evaluated before a operator of lower precedence and the operands of an operator are evaluated based on associativity. The following table describes the precedence and associativity of the C and C++ operators. Operators are shown in groups of equal precedence with groups ordered in descending precedence from top to bottom (lower order is higher precedence). [ 8 ] [ 9 ] [ 10 ] Operator precedence is not affected by overloading. Although this table is adequate for describing most evaluation order, it does not describe a few details. The ternary operator allows any arbitrary expression as its middle operand, despite being listed as having higher precedence than the assignment and comma operators. Thus a ? b, c : d is interpreted as a ? (b, c) : d , and not as the meaningless (a ? b), (c : d) . So, the expression in the middle of the conditional operator (between ? and : ) is parsed as if parenthesized. Also, the immediate, un-parenthesized result of a C cast expression cannot be the operand of sizeof . Therefore, sizeof (int) * x is interpreted as (sizeof(int)) * x and not sizeof ((int) * x) . Chained expressions The precedence table determines the order of binding in chained expressions, when it is not expressly specified by parentheses. For example, ++x*3 is ambiguous without some precedence rule(s). The precedence table tells us that: x is 'bound' more tightly to ++ than to * , so that whatever ++ does (now or later—see below), it does it ONLY to x (and not to x*3 ); it is equivalent to ( ++x , x*3 ). Similarly, with 3*x++ , where though the post-fix ++ is designed to act AFTER the entire expression is evaluated, the precedence table makes it clear that ONLY x gets incremented (and NOT 3*x ). In fact, the expression ( tmp=x++ , 3*tmp ) is evaluated with tmp being a temporary value. It is functionally equivalent to something like ( tmp=3*x , ++x , tmp ). Abstracting the issue of precedence or binding, consider the diagram above for the expression 3+2*y[i]++. The compiler's job is to resolve the diagram into an expression, one in which several unary operators (call them 3+( . ), 2*( . ), ( . )++ and ( . )[ i ]) are competing to bind to y. The order of precedence table resolves the final sub-expression they each act upon: ( . )[ i ] acts only on y, ( . )++ acts only on y[i], 2*( . ) acts only on y[i]++ and 3+( . ) acts 'only' on 2*((y[i])++). WHAT sub-expression gets acted on by each operator is clear from the precedence table but WHEN each operator acts is not resolved by the precedence table; in this example, the ( . )++ operator acts only on y[i] by the precedence rules but binding levels alone do not indicate the timing of the postfix ++ (the ( . )++ operator acts only after y[i] is evaluated in the expression). The binding of operators in C and C++ is specified by a factored language grammar, rather than a precedence table. This creates some subtle conflicts. For example, in C, the syntax for a conditional expression is: while in C++ it is: Hence, the expression: is parsed differently in the two languages. In C, this expression is a syntax error, because the syntax for an assignment expression in C is: In C++, it is parsed as: which is a valid expression. [ 11 ] [ 12 ] To use the comma operator in a function call argument expression, variable assignment, or a comma-separated list, use of parentheses is required. [ 13 ] [ 14 ] For example, Criticism of bitwise and equality operators precedence The precedence of the bitwise logical operators has been criticized. [ 15 ] Conceptually, & and | are arithmetic operators like * and +. The expression a & b == 7 is syntactically parsed as a & ( b == 7 ) whereas the expression a + b == 7 is parsed as ( a + b ) == 7 . This requires parentheses to be used more often than they otherwise would. Historically, there was no syntactic distinction between the bitwise and logical operators. In BCPL , B and early C, the operators && || didn't exist. Instead & | had different meaning depending on whether they are used in a 'truth-value context' (i.e. when a Boolean value was expected, for example in if ( a == b & c ) {...} it behaved as a logical operator, but in c = a & b it behaved as a bitwise one). It was retained so as to keep backward compatibility with existing installations. [ 16 ] Moreover, in C++ (and later versions of C) equality operations, with the exception of the three-way comparison operator, yield bool type values which are conceptually a single bit (1 or 0) and as such do not properly belong in "bitwise" operations. ↑ The modulus operator only supports integer operands; for floating point, a function such as fmod can be used. 1 2 3 4 The int is a dummy parameter to differentiate between prefix and postfix. ↑ About C++20 three-way comparison ↑ Possible return types: std::weak_ordering , std::strong_ordering and std::partial_ordering to which they all are convertible to. 1 2 In the context of iostreams in C++, writers often will refer to << and >> as the "put-to" or "stream insertion" and "get-from" or "stream extraction" operators, respectively. ↑ According to the C99 standard, the right shift of a negative number is implementation defined. Most implementations, e.g., the GCC, [ 3 ] use an arithmetic shift (i.e., sign extension), but a logical shift is possible. ↑ According to the C99 standard, the right shift of a negative number is implementation defined. Most implementations, e.g., the GCC, [ 3 ] use an arithmetic shift (i.e., sign extension), but a logical shift is possible. 1 2 3 since C++23 ↑ The actual address of an object with an overloaded operator & can be obtained with std::addressof ↑ The return type of operator -> () must be a type for which the -> operation can be applied, such as a pointer type. If x is of type C where C overloads operator -> () , x -> y gets expanded to x . operator -> () -> y . ↑ Meyers, Scott (October 1999), "Implementing operator- > * for Smart Pointers" (PDF) , Dr. Dobb's Journal , Aristeia . ↑ Although a :: punctuator exists in C as of C23, it is not used as a scope resolution operator. ↑ About C++11 User-defined literals 1 2 3 4 5 6 7 8 since C++11 ↑ The parentheses are not necessary when taking the size of a value, only when taking the size of a type. However, they are usually used regardless. [ citation needed ] ↑ C++ defines alignof operator, whereas C defines _Alignof (C23 defines both). Both operators have the same semantics. ↑ since C23; not in standard C++ ↑ Behaves like const_cast/static_cast/reinterpret_cast. In the last two cases, the auto specifier is replaced with the type of the invented variable x declared with auto x(a); (which is never interpreted as a function declaration) or auto x{a}; , respectively. ↑ For user-defined conversions, the return type implicitly and necessarily matches the operator name unless the type is inferred (e.g. operator auto () , operator decltype ( auto )() etc.). ↑ The type name can also be inferred (e.g new auto ) if an initializer is provided. ↑ The array size can also be inferred if an initializer is provided. Bitwise operations in C – Operations transforming individual bits of integral data types Bit manipulation – Algorithmically modifying data below the word level Logical operator – Symbol connecting formulas in logic Pages displaying short descriptions of redirect targets Boolean algebra (logic) – Algebraic manipulation of "true" and "false" Pages displaying short descriptions of redirect targets Table of logic symbols ↑ "Operator overloading§Comparison operators" . cppreference.com . ↑ "Standard C++" . 1 2 "Integers implementation", GCC 4.3.3 , GNU .

↑ "ISO/IEC 9899:1999 specification, TC3" (PDF) . p. 64, § 6.4.6 Ponctuators para. 3. ↑ "user-defined conversion" . Retrieved 5 April 2020 . ↑ Explicit type conversion in C++ ↑ ISO/IEC 14882:1998(E) Programming Language C++ . open-std.org – The C++ Standards Committee. 1 September 1998. pp. 40– 41. ↑ ISO/IEC 9899:201x Programming Languages - C . open-std.org – The C Standards Committee. 19 December 2011. p. 465. ↑ the ISO C 1999 standard, section 6.5.6 note 71 (Technical report). ISO. 1999. ↑ "C++ Built-in Operators, Precedence and Associativity" . docs.microsoft.com . Retrieved 11 May 2020 . ↑ "C Operator Precedence - cppreference.com" . en.cppreference.com . Retrieved 10 April 2020 . ↑ "Does the C/C++ ternary operator actually have the same precedence as assignment operators?" . Stack Overflow . Retrieved 22 September 2019 . ↑ "Other operators - cppreference.com" . en.cppreference.com . Retrieved 10 April 2020 . ↑ "c++ - How does the Comma Operator work" . Stack Overflow . Retrieved 1 April 2020 . ↑ C history § Neonatal C , Bell labs . ↑ "Re^10: next unless condition" . www.perlmonks.org . Retrieved 23 March 2018 . "Operators", C++ reference (wiki) . C Operator Precedence Postfix Increment and Decrement Operators: ++ and -- (Developer network), Microsoft, 17 August 2021 . Freestanding implementation Bionic libhybris Borland Turbo C IAR Embedded Workbench Visual C++ (MSVC) Compatibility of C and C++ Comparison with Pascal Special member functions Exception handling ( Exception safety ) Function overloading Operator overloading Virtual functions Placement syntax Functional wrappers Sequence containers Ordered associative containers Unordered associative containers Barton–Nackman trick constant expressions Curiously recurring template pattern Most vexing parse One Definition Rule Resource acquisition is initialization Special member functions Substitution failure is not an error Template metaprogramming Comparison of C++ compilers Borland Turbo C++ IAR Embedded Workbench Intel C++ Compiler Oracle Solaris Studio Visual C++ (MSVC) Comparison of C IDEs Comparison of programming languages Comparison of Java and C++ Compatibility of C and C++ Andrei Alexandrescu Alexander Stepanov Bjarne Stroustrup C (programming language) Operators (programming) Comparison of individual programming languages Articles with short description Short description is different from Wikidata Use American English from March 2019 All Wikipedia articles written in American English Use dmy dates from December 2019 Articles with example C++ code All articles with unsourced statements Articles with unsourced statements from July 2024 Pages displaying short descriptions of redirect targets via Module:Annotated link