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)
Misconceptions about Operator30 documented Misconceptions
Check YourselfArithmeticPlusPrecedes — Java
Addition has higher precedence than string concatenation
ArrayAccessWithParentheses — Java
Parentheses are used to access an element in an array
AssignCompares — Java
= compares two values
AssignmentNotExpression — Java
An assignment a=b is not an expression
CannotChainMemberAccesses — Java
Member accesses cannot be chained together
CannotChainMemberToConstructor — Java
Method calls or field accesses cannot be chained to a constructor invocation
ComparisonWithBooleanLiteral — Java
To test whether an expression is true or false, one must compare it to true or to false
EqualityOperatorComparesObjectsValues — Java
o==p compares the objects referred to by variables o and p
MapToBooleanWithConditionalOperator — Java
To map a boolean expression to a boolean, a conditional operator is necessary
NoAtomicExpression — Java
Expressions must consist of more than one piece
NoShortCircuit — Java
&& and || always evaluate both operands
NoSingleLogicAnd — Java
& is only a bitwise AND
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
ConditionalOperatorNotExpression — JavaScript
The conditional operator is not an expression
EqualityOperatorComparesObjectsValues — JavaScript
The equality operator compares two objects' values
EqualityOperatorComparesOnlyTypes — JavaScript
The equality operator '==' compares only the types of the operands
NoAtomicExpression — JavaScript
Expressions must consist of more than one piece
AssignCompares — Python
= compares two values
CannotChainAttributeAccesses — Python
Attribute accesses cannot be chained together
CannotChainAttributeToObjectInstantiation — Python
Method calls, and attribute accesses in general, cannot be chained to a constructor invocation.
ComparisonWithBoolLiteral — Python
To test whether an expression is True or False, one must compare it to True or to False
MapToBooleanWithTernaryOperator — Python
To map a boolean expression to a bool, a ternary conditional operator is necessary
NoAtomicExpression — Python
Expressions must consist of more than one piece
NoShortCircuit — Python
and/or always evaluate both operands
NoSingleLogicAnd — Python
& is only a bitwise AND
PlusConcatenatesNumbers — Python
The plus operator can concatenate strings and numbers
CompareBooleanToConstant — Scratch
To test whether an expression evaluates to true or false, one must compare it to a constant
EqualityOperatorComparesOnlyTypes — Scratch
() = () compares only the types of its operands