Programming languages typically support a set of operators: operations which differ from the language's functions in calling syntax and/or argument passing mode. Common examples that differ by syntax are mathematical arithmetic operations, e.g. ">" for "greater than", with names often outside the language's set of identifiers for functions, and called with a syntax different from the language's syntax for calling functions. Common examples that differ by argument passing mode are boolean operations, e.g. a short-circuiting conjunction that only evaluates later arguments if earlier ones are not false, in a language with strict call-by-value functions.

A language may contain a fixed number of built-in operators (e.g. + - * = in C and C++

Operators in C and C++

This is a list of operators in the C and C++ programming languages. All the operators listed exist in C++; the fourth column "Included in C", dictates whether an operator is also present in C...

), or it may allow the creation of programmer-defined operators (e.g. Haskell). Some programming languages restrict operator symbols to special characters like +

Addition

Addition is a mathematical operation that represents combining collections of objects together into a larger collection. It is signified by the plus sign . For example, in the picture on the right, there are 3 + 2 apples—meaning three apples and two other apples—which is the same as five apples....

 or :=

Assignment (computer science)

In computer programming, an assignment statement sets or re-sets the value stored in the storage location denoted by a variable name. In most imperative computer programming languages, assignment statements are one of the basic statements...

 while others allow also names like div (e.g. Pascal

Pascal (programming language)

Pascal is an influential imperative and procedural programming language, designed in 1968/9 and published in 1970 by Niklaus Wirth as a small and efficient language intended to encourage good programming practices using structured programming and data structuring.A derivative known as Object Pascal...

).

Some built-in operators supported by a language have a direct mapping to a small number of instructions

Machine code

Machine code or machine language is a system of impartible instructions executed directly by a computer's central processing unit. Each instruction performs a very specific task, typically either an operation on a unit of data Machine code or machine language is a system of impartible instructions...

 commonly found on central processing units, though others (e.g. '+' used to express string concatenation) may have complicated implementations.

The specification of a language will specify the precedence

Order of operations

In mathematics and computer programming, the order of operations is a rule used to clarify unambiguously which procedures should be performed first in a given mathematical expression....

 and associativity

Associativity

In mathematics, associativity is a property of some binary operations. It means that, within an expression containing two or more occurrences in a row of the same associative operator, the order in which the operations are performed does not matter as long as the sequence of the operands is not...

 of the operators it supports. Languages which support programmer-defined operators require the specification of the precedence and associativity of new operator symbols (e.g. Prolog

Prolog

Prolog is a general purpose logic programming language associated with artificial intelligence and computational linguistics.Prolog has its roots in first-order logic, a formal logic, and unlike many other programming languages, Prolog is declarative: the program logic is expressed in terms of...

).

Most programming language operators take one or two operands, with a few supporting more operands (e.g., the ?:

?:

In computer programming, ?: is a ternary operator that is part of the syntax for a basic conditional expression in several programming languages...

 operator in C). The position of the operator with respect to its operands may be prefix

Polish notation

Polish notation, also known as prefix notation, is a form of notation for logic, arithmetic, and algebra. Its distinguishing feature is that it places operators to the left of their operands. If the arity of the operators is fixed, the result is a syntax lacking parentheses or other brackets that...

, infix

Infix notation

Infix notation is the common arithmetic and logical formula notation, in which operators are written infix-style between the operands they act on . It is not as simple to parse by computers as prefix notation or postfix notation Infix notation is the common arithmetic and logical formula notation,...

 or postfix.

Syntactically operators usually contrast to functions. In most languages, functions may be seen as a special form of prefix operator with fixed precedence level and associativity, often with compulsory parentheses e.g. Func(a) (or (Func a) in LISP). Most languages support programmer-defined functions, but cannot really claim to support programmer-defined operators, unless they have more than prefix notation and more than a single precedence level. Semantically operators can be seen as special form of function with different calling notation and a limited number of parameters (usually 1 or 2).

A compiler can implement operators and functions with subroutine calls

Subroutine

In computer science, a subroutine is a portion of code within a larger program that performs a specific task and is relatively independent of the remaining code....

 or with inline code

Inline expansion

In computing, inline expansion, or inlining, is a manual or compiler optimization that replaces a function call site with the body of the callee. This optimization may improve time and space usage at runtime, at the possible cost of increasing the final size of the program In computing, inline...

.

Operator overloading

In some programming languages an operator may be ad-hoc polymorphic, that is, have definitions for more than one kind of data, (such as in Java

Java (programming language)

Java is a programming language originally developed by James Gosling at Sun Microsystems and released in 1995 as a core component of Sun Microsystems' Java platform. The language derives much of its syntax from C and C++ but has a simpler object model and fewer low-level facilities...

 where the + operator is used both for the addition of numbers and for the concatenation of strings). Such an operator is said to be overloaded. In languages that support operator overloading by the programmer but have a limited set of operators, operator overloading is often used to define customized uses for operators.

Operand coercion

Some languages also allow for the operands of an operator to be implicitly converted, or coerced, to suitable data types for the operation to occur. For example, in Perl

Perl

Perl is a high-level, general-purpose, interpreted, dynamic programming language. Perl was originally developed by Larry Wall in 1987 as a general-purpose Unix scripting language to make report processing easier. Since then, it has undergone many changes and revisions and become widely popular...

 coercion rules lead into 12 + "3.14" producing the result of 15.14. The text "3.14" is converted to the number 3.14 before addition can take place. Further, 12 is an integer and 3.14 is either a floating or fixed-point number (a number that has a decimal place in it) so the integer is then converted to a floating point or fixed-point number respectively.

Javascript

JavaScript

JavaScript is a prototype-based scripting language that is dynamic, weakly typed and has first-class functions. It is a multi-paradigm language, supporting object-oriented, imperative, and functional programming styles....

 follows opposite rules—finding the same expression above, it will convert the integer 12 into a string "12", then concatenate the two operands to form "123.14".

In the presence of coercions in a language, the programmer must be aware of the specific rules regarding operand types and the operation result type to avoid subtle programming mistakes.

Operator features in programming languages

The following table shows the operator features in several programming languages:

Programming language	Nonalphanumeric operator symbols	Alphanumeric operator symbols	Prefix	Infix	Postfix	Precedence	Associativity	Overloading	Programmer-defined overloading	Programmer-defined operator symbols
ALGOL 68 ALGOL 68 ALGOL 68 isan imperative computerprogramming language that was conceived as a successor to theALGOL 60 programming language, designed with the goal of a...	+* ** * / % %* %× - + < <= >= > = /= & -:= +:= *:= /:= %:= %*:= +=: :=: :/=: (All operators have bold Alphanumeric equivalents, c.f. next column. Some have non ASCII ASCII The American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...  equivalents, c.f. below.) ¬ +× ⊥ ↑ ↓ ⌊ ⌈ × ÷ ÷× ÷* □ ≤ ≥ ≠ ∧ ∨ ×:= ÷:= ÷×:= ÷*:= %×:= :≠:	not abs arg bin entier leng level odd repr round shorten i shl shr up down lwb upb lt le ge gt eq ne and or over mod elem minusab plusab timesab divab overab modab plusto is isnt				(prefix operators always have priority 10)	Infix operators are left associative, prefix operators are right associative
C C (programming language) C is a general-purpose computer programming language developed between 1969 and 1973 by Dennis Ritchie at the Bell Telephone Laboratories for use with the Unix operating system....	[] -> . ! ~ ++ -- + - * & / % << >> < <= > <= != ^ | &&	?: ?: In computer programming, ?: is a ternary operator that is part of the syntax for a basic conditional expression in several programming languages...  = += -= *= /= %= &= ^= >= <<= >>=	sizeof Sizeof In the programming languages C and C++, the unary operator sizeof is used to calculate the sizes of datatypes, in number of bytes. A byte in this context is the same as an unsigned char, and may be larger than the standard 8 bits, although that is uncommon in modern implementations...
C++ C++ C++ is a statically typed, free-form, multi-paradigm, compiled, general-purpose programming language. It is regarded as an intermediate-level language, as it comprises a combination of both high-level and low-level language features. It was developed by Bjarne Stroustrup starting in 1979 at Bell...  (more Operators in C and C++ This is a list of operators in the C and C++ programming languages. All the operators listed exist in C++; the fourth column "Included in C", dictates whether an operator is also present in C... )		sizeof Sizeof In the programming languages C and C++, the unary operator sizeof is used to calculate the sizes of datatypes, in number of bytes. A byte in this context is the same as an unsigned char, and may be larger than the standard 8 bits, although that is uncommon in modern implementations...  new delete throw Exception handling Exception handling is a programming language construct or computer hardware mechanism designed to handle the occurrence of exceptions, special conditions that change the normal flow of program execution....
Java Java (programming language) Java is a programming language originally developed by James Gosling at Sun Microsystems and released in 1995 as a core component of Sun Microsystems' Java platform. The language derives much of its syntax from C and C++ but has a simpler object model and fewer low-level facilities...		new instanceof
Haskell Haskell (programming language) Haskell is a standardized, general-purpose purely functional programming language, with non-strict semantics and strong static typing. It is named after logician Haskell Curry. In Haskell, "a function is a first-class citizen" of the programming language. As a functional programming language, the...	+ - * / ^ ^^ ** /= > < >= <= && || >>= >> $ $! . ++ !! : Many more in common libraries	Yes, by putting a function's name into backticks						colspan="2" , using Type class Type class In computer science, a type class is a type system construct that supports ad-hoc polymorphism. This is achieved by adding constraints to type variables in parametrically polymorphic types... es
Pascal Pascal (programming language) Pascal is an influential imperative and procedural programming language, designed in 1968/9 and published in 1970 by Niklaus Wirth as a small and efficient language intended to encourage good programming practices using structured programming and data structuring.A derivative known as Object Pascal...	* / + - = < > <> <= >= :=	not div mod Modulo operation In computing, the modulo operation finds the remainder of division of one number by another.Given two positive numbers, and , a modulo n can be thought of as the remainder, on division of a by n...  and Logical conjunction In logic and mathematics, a two-place logical operator and, also known as logical conjunction, results in true if both of its operands are true, otherwise the value of false....  or Logical disjunction In logic and mathematics, a two-place logical connective or, is a logical disjunction, also known as inclusive disjunction or alternation, that results in true whenever one or more of its operands are true. E.g. in this context, "A or B" is true if A is true, or if B is true, or if both A and B are...  in
Seed7	** ! + - * / << >> & >< > = <> > >= < <= <& := +:= -:= *:= /:= <<:= >>:= &:= @:=	conv varConv parse conj Complex conjugate In mathematics, complex conjugates are a pair of complex numbers, both having the same real part, but with imaginary parts of equal magnitude and opposite signs...  div rem Remainder In arithmetic, the remainder is the amount "left over" after the division of two integers which cannot be expressed with an integer quotient....  mdiv Modulo operation In computing, the modulo operation finds the remainder of division of one number by another.Given two positive numbers, and , a modulo n can be thought of as the remainder, on division of a by n...  mod Modulo operation In computing, the modulo operation finds the remainder of division of one number by another.Given two positive numbers, and , a modulo n can be thought of as the remainder, on division of a by n...  times mult in not and Logical conjunction In logic and mathematics, a two-place logical operator and, also known as logical conjunction, results in true if both of its operands are true, otherwise the value of false....  or Logical disjunction In logic and mathematics, a two-place logical connective or, is a logical disjunction, also known as inclusive disjunction or alternation, that results in true whenever one or more of its operands are true. E.g. in this context, "A or B" is true if A is true, or if B is true, or if both A and B are...  digits lpad rpad lpad0
Prolog Prolog Prolog is a general purpose logic programming language associated with artificial intelligence and computational linguistics.Prolog has its roots in first-order logic, a formal logic, and unlike many other programming languages, Prolog is declarative: the program logic is expressed in terms of...	:- ?- ; , . =.. = \= < =< >= > \ - + / *	spy nospy not is mod
Lisp	+ - * / = /= < <= > >=	mod rem floor truncate min max	(operator and parameters must be surrounded by parentheses)
Smalltalk Smalltalk Smalltalk is an object-oriented, dynamically typed, reflective programming language. Smalltalk was created as the language to underpin the "new world" of computing exemplified by "human–computer symbiosis." It was designed and created in part for educational use, more so for constructionist...	(yes - Up to two characters)	(yes - Needs a colon after the keyword)