Variable

A variable is a named location that holds a value.

Related concepts:  NameValueAssignment

Closest Wikipedia entry:  Variable (computer science)

Misconceptions about Variable

35 documented Misconceptions

AssignmentCopiesObject

Assignment copies the object

CallerFrameContainsCalleeFormal

Stack frame of caller includes variables for callee's formal parameters

ControlledLocalAccess

One can control access to local variables using access modifiers

ExpressionAssigns

An expression that reads a variable also updates its value after the evaluation

ForEachIteratesOverIndices

An enhanced for loop iterates over the indices of an array or a collection

ForEachVariableIsElement

One can assign to the variable of an enhanced for statement to store a value in the corresponding array or collection element

ForVariableScopeBeyondLoop

The scope of variables declared in a for loop header extends beyond the loop

LocalVariablesAutoInitialized

Local variables are automatically initialized

LoopBodyScopeImpliesLoopLifetime

Lifetime of variables declared in a loop body extends across all loop iterations

MultiReferenceVariable

A reference variable can point to multiple objects

MultiValueVariable

A variable can contain more than one value

MustInitializeFieldInConstructor

Constructors must assign values to all fields

NoAtomicExpression

Expressions must consist of more than one piece

NoCastIfSameSize

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

NoLocalVariables

There are no local variables

ReferenceToVariable

References can point to variables

ThisAsField

this is a special field in the object

ThisAssignable

One can assign to this

ThisExistsInStaticMethod

this is a local variable, also in static methods

UndeclaredVariables

Variables can be used even without being declared beforehand

UntypedVariables

Variable declarations don't need a type

UseOfSelfTypeImpliesRecursiveType

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

= stores an expression in a variable

VariablesHoldObjects

A variable of a reference type contains a whole object