Operator

An operator is a symbol or keyword in source code that represents a built-in function.

Related concepts:  Function

Closest Wikipedia entry:  Operator (computer programming) — In computer programming, operators are constructs defined within programming languages which behave generally like functions, but which differ syntactically or semantically. Common simple examples include arithmetic (e.g. addition with +), comparison (e.g. "greater than" with >), and logical operations (e.g. AND, also written && in some languages). More involved examples include assignment (usually = or :=), field access in a record or object (usually .), and the scope resolution operator (often :: or .).

Misconceptions about Operator

28 documented Misconceptions

ArithmeticPlusPrecedes — Java

Addition has higher precedence than string concatenation

ArrayAccessWithParentheses — Java

Parenthesis are used to access an element in an array

AssignCompares — Java

= compares two values

AssignCompares — Python

= compares two values

AssignmentNotExpression — Java

An assignment a=b is not an expression

CannotChainAttributeToObjectInstantiation — Python

Method calls, and attribute accesses in general, cannot be chained to a constructor invocation.

CannotChainMemberAccesses — Java

Member accesses cannot be chained together

CannotChainMemberToConstructor — Java

Method calls or field accesses cannot be chained to a constructor invocation

CompareBooleanToConstant — Scratch

To test whether an expression evaluates to true or false, one must compare it to a constant

ComparisonWithBoolLiteral — Python

To test whether an expression is True or False, one must compare it to True or to False

ComparisonWithBooleanLiteral — Java

To test whether an expression is true or false, one must compare it to true or to false

ConditionalOperatorNotExpression — JavaScript

The conditional operator is not an expression

EqualityOperatorComparesObjectsValues — Java

o==p compares the objects referred to by variables o and p

EqualityOperatorComparesObjectsValues — JavaScript

The equality operator compares two objects' values

EqualityOperatorComparesOnlyTypes — JavaScript

The equality operator '==' compares only the types of the operands

EqualityOperatorComparesOnlyTypes — Scratch

() = () compares only the types of its operands

MapToBooleanWithConditionalOperator — Java

To map a boolean expression to a boolean, a conditional operator is necessary

MapToBooleanWithTernaryOperator — Python

To map a boolean expression to a bool, a ternary conditional operator is necessary

NoAtomicExpression — Java

Expressions must consist of more than one piece

NoAtomicExpression — JavaScript

Expressions must consist of more than one piece

NoAtomicExpression — Python

Expressions must consist of more than one piece

NoShortCircuit — Java

&& and || always evaluate both operands

NoShortCircuit — Python

and/or always evaluate both operands

NoSingleLogicAnd — Java

& is only a bitwise AND

PlusConcatenatesNumbers — Python

The plus operator can concatenate strings and numbers

PreIncrementBeforeLoop — Java

Pre-increment in update part of for loop means increment before loop body

RightToLeftChaining — Java

Chained accesses are invoked from right to left

StringPlusStringifiesExpression — Java

String concatenation stringifies non-String operand expressions