Value

A value is data and may be the result of evaluating an expression or the contents of a variable.

Related concepts:  ValueEvaluationVariable

Closest Wikipedia entry:  Value (computer science) — In computer science and software programming, a value is the representation of some entity that can be manipulated by a program. The members of a type are the values of that type.The "value of a variable" is given by the corresponding mapping in the environment. In languages with assignable variables, it becomes necessary to distinguish between the r-value (or contents) and the l-value (or location) of a variable.In declarative (high-level) languages, values have to be referentially transparent.

Misconceptions about Value

26 documented Misconceptions

AssignmentCopiesObject — Python

Assignment copies the object

CallbackParametersInCaller — JavaScript

Parameters of a callback function may be written as parameters of the caller function

EqualityOperatorComparesListIdentities — Scratch

(list a) = (list b) compares the identities of list a and list b

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

EqualsComparesReferences — Java

o.equals(p) compares the references stored in the variables o and p

ExpressionsDynamicallyTyped — Java

One has to evaluate an expression to determine its type

FunctionAsValueWithParentheses — JavaScript

To use a function as a value, one needs to have parentheses after its name

LocalVariablesAutoInitialized — Java

Local variables are automatically initialized

MultiValueVariable — Java

A variable can contain more than one value

MultipleValuesReturn — Python

Functions can return multiple values

MustInitializeFieldInConstructor — Java

Constructors must assign values to all fields

NoCastIfSameSize — Java

If a variable is at least as big (bit-width) as a value, then no cast is needed to a assign the value to the variable

NoReturnValue — JavaScript

Functions without return statements return no value at all

NullAndUndefinedAreTheSame — JavaScript

The values null and undefined are the same

NullIsObject — Java

null is an object

NullIsObject — JavaScript

null is an object

PrimitiveIsObject — Java

Primitive values are heap objects

PrimitiveVariablesDynamicallyTyped — Java

The type of a primitive variable depends on its value

TypeofNullIsNull — JavaScript

The value null is of type 'null'

UseOfSelfTypeImpliesRecursiveType — Java

If a class has a method that has a local variable, parameter, or return value with the class as its type, the class is a recursive type

VariablesHoldExpressions — Python

= stores an expression: it stores a reference to the expression in a variable

VariablesHoldObjects — Python

A variable contains a whole object

VoidMethodReturnsValue — Java

A method with void return type can return a value