com.github.javaparser.ast.expr

Class InstanceOfExpr

java.lang.Object

com.github.javaparser.ast.Node

com.github.javaparser.ast.expr.Expression

com.github.javaparser.ast.expr.InstanceOfExpr

All Implemented Interfaces:

NodeWithExpression<InstanceOfExpr>, NodeWithRange<Node>, NodeWithTokenRange<Node>, NodeWithType<InstanceOfExpr,ReferenceType>, Observable, Visitable, HasParentNode<Node>, Cloneable

public class InstanceOfExpr
extends Expression
implements NodeWithType<InstanceOfExpr,ReferenceType>, NodeWithExpression<InstanceOfExpr>

The instanceof statement

Java ?? to 13

The instanceof expression is a relational operator, evaluating to true if the object on the left hand side is an instance of the type (ReferenceType) on the right hand side.

Example:
tool instanceof Drill

This is then used wherever a conditional/boolean value can be used. For example:

 if (obj instanceof String) {
     String s = (String) obj;
     // use s
 }

Java 14

Since JDK14, it is possible to bind a variable that is cast to the type being tested against. This is referred to as a Pattern within JEP305, and avoids the need to cast to the desired type.
Example:
tool instanceof Drill d

This is then used wherever a conditional/boolean value can be used. The scope of the variable created can vary, and is defined further within JEP305.

 if (obj instanceof String s) {
     // can use s here
 } else {
     // can't use s here
 }

JDK14 Grammar

Per JEP305:

 RelationalExpression:
      ...
      RelationalExpression instanceof ReferenceType
      RelationalExpression instanceof Pattern

 Pattern:
      ReferenceType Identifier

Author:

Julio Vilmar Gesser

See Also:

PatternExpr, JEP305: https://bugs.openjdk.java.net/browse/JDK-8181287, https://docs.oracle.com/javase/specs/jls/se11/html/jls-15.html#jls-15.20

Nested Class Summary

Nested classes/interfaces inherited from class com.github.javaparser.ast.Node

Node.BreadthFirstIterator, Node.DirectChildrenIterator, Node.ObserverRegistrationMode, Node.ParentsVisitor, Node.Parsedness, Node.PostOrderIterator, Node.PreOrderIterator, Node.TreeTraversal

Field Summary

Fields inherited from class com.github.javaparser.ast.expr.Expression

EXCLUDE_ENCLOSED_EXPR, IS_NOT_ENCLOSED_EXPR

Fields inherited from class com.github.javaparser.ast.Node

ABSOLUTE_BEGIN_LINE, ABSOLUTE_END_LINE, LINE_SEPARATOR_KEY, NODE_BY_BEGIN_POSITION, PHANTOM_KEY, prettyPrinterNoCommentsConfiguration, PRINTER_KEY, SYMBOL_RESOLVER_KEY

Constructor Summary

Constructors

Constructor and Description
InstanceOfExpr()
InstanceOfExpr(Expression expression, ReferenceType type)
InstanceOfExpr(Expression expression, ReferenceType type, PatternExpr pattern)
InstanceOfExpr(TokenRange tokenRange, Expression expression, ReferenceType type, PatternExpr pattern) This constructor is used by the parser and is considered private.

Method Summary

Modifier and Type	Method and Description
<R,A> R	accept(GenericVisitor<R,A> v, A arg) Accept method for visitor support.
<A> void	accept(VoidVisitor<A> v, A arg) Accept method for visitor support.
InstanceOfExpr	asInstanceOfExpr()
InstanceOfExpr	clone()
Expression	getExpression()
InstanceOfExprMetaModel	getMetaModel()
Optional<SimpleName>	getName() Helper method which, if this is an expression with a type pattern, returns the identifier/name.
Optional<PatternExpr>	getPattern()
ReferenceType	getType() Gets the type
void	ifInstanceOfExpr(Consumer<InstanceOfExpr> action)
boolean	isInstanceOfExpr()
boolean	remove(Node node)
InstanceOfExpr	removePattern()
boolean	replace(Node node, Node replacementNode)
InstanceOfExpr	setExpression(Expression expression)
InstanceOfExpr	setPattern(PatternExpr pattern)
InstanceOfExpr	setType(ReferenceType type) Sets the type
Optional<InstanceOfExpr>	toInstanceOfExpr()

Methods inherited from class com.github.javaparser.ast.expr.Expression

appearsInAssignmentContext, appearsInInvocationContext, asAnnotationExpr, asArrayAccessExpr, asArrayCreationExpr, asArrayInitializerExpr, asAssignExpr, asBinaryExpr, asBooleanLiteralExpr, asCastExpr, asCharLiteralExpr, asClassExpr, asConditionalExpr, asDoubleLiteralExpr, asEnclosedExpr, asFieldAccessExpr, asIntegerLiteralExpr, asLambdaExpr, asLiteralExpr, asLiteralStringValueExpr, asLongLiteralExpr, asMarkerAnnotationExpr, asMethodCallExpr, asMethodReferenceExpr, asNameExpr, asNormalAnnotationExpr, asNullLiteralExpr, asObjectCreationExpr, asPatternExpr, asRecordPatternExpr, asSingleMemberAnnotationExpr, asStringLiteralExpr, asSuperExpr, asSwitchExpr, asTextBlockLiteralExpr, asThisExpr, asTypeExpr, asTypePatternExpr, asUnaryExpr, asVariableDeclarationExpr, calculateResolvedType, elidesTypeArguments, ifAnnotationExpr, ifArrayAccessExpr, ifArrayCreationExpr, ifArrayInitializerExpr, ifAssignExpr, ifBinaryExpr, ifBooleanLiteralExpr, ifCastExpr, ifCharLiteralExpr, ifClassExpr, ifConditionalExpr, ifDoubleLiteralExpr, ifEnclosedExpr, ifFieldAccessExpr, ifIntegerLiteralExpr, ifLambdaExpr, ifLiteralExpr, ifLiteralStringValueExpr, ifLongLiteralExpr, ifMarkerAnnotationExpr, ifMethodCallExpr, ifMethodReferenceExpr, ifNameExpr, ifNormalAnnotationExpr, ifNullLiteralExpr, ifObjectCreationExpr, ifPatternExpr, ifRecordPatternExpr, ifSingleMemberAnnotationExpr, ifStringLiteralExpr, ifSuperExpr, ifSwitchExpr, ifTextBlockLiteralExpr, ifThisExpr, ifTypeExpr, ifTypePatternExpr, ifUnaryExpr, ifVariableDeclarationExpr, isAnnotationExpr, isArrayAccessExpr, isArrayCreationExpr, isArrayInitializerExpr, isAssignExpr, isAssignmentContext, isBinaryExpr, isBooleanLiteralExpr, isCastExpr, isCharLiteralExpr, isClassExpr, isConditionalExpr, isDoubleLiteralExpr, isEnclosedExpr, isFieldAccessExpr, isIntegerLiteralExpr, isInvocationContext, isLambdaExpr, isLiteralExpr, isLiteralStringValueExpr, isLongLiteralExpr, isMarkerAnnotationExpr, isMethodCallExpr, isMethodReferenceExpr, isNameExpr, isNormalAnnotationExpr, isNullLiteralExpr, isObjectCreationExpr, isPatternExpr, isPolyExpression, isQualified, isRecordPatternExpr, isSingleMemberAnnotationExpr, isStandaloneExpression, isStringLiteralExpr, isSuperExpr, isSwitchExpr, isTextBlockLiteralExpr, isThisExpr, isTypeExpr, isTypePatternExpr, isUnaryExpr, isVariableDeclarationExpr, toAnnotationExpr, toArrayAccessExpr, toArrayCreationExpr, toArrayInitializerExpr, toAssignExpr, toBinaryExpr, toBooleanLiteralExpr, toCastExpr, toCharLiteralExpr, toClassExpr, toConditionalExpr, toDoubleLiteralExpr, toEnclosedExpr, toFieldAccessExpr, toIntegerLiteralExpr, toLambdaExpr, toLiteralExpr, toLiteralStringValueExpr, toLongLiteralExpr, toMarkerAnnotationExpr, toMethodCallExpr, toMethodReferenceExpr, toNameExpr, toNormalAnnotationExpr, toNullLiteralExpr, toObjectCreationExpr, toPatternExpr, toRecordPatternExpr, toSingleMemberAnnotationExpr, toStringLiteralExpr, toSuperExpr, toSwitchExpr, toTextBlockLiteralExpr, toThisExpr, toTypeExpr, toTypePatternExpr, toUnaryExpr, toVariableDeclarationExpr

Methods inherited from class com.github.javaparser.ast.Node

addOrphanComment, containsData, createDefaultPrinter, createDefaultPrinter, customInitialization, equals, findAll, findAll, findAll, findByRange, findCompilationUnit, findData, findFirst, findFirst, findFirst, findRootNode, getAllContainedComments, getChildNodes, getChildNodesByType, getComment, getData, getDataKeys, getDefaultPrinterConfiguration, getLineEndingStyle, getLineEndingStyleOrDefault, getNodesByType, getOrphanComments, getParentNode, getParentNodeForChildren, getParsed, getPrinter, getPrinter, getRange, getSymbolResolver, getTokenRange, hashCode, hasScope, isAncestorOf, isPhantom, isRegistered, notifyPropertyChange, register, register, registerForSubtree, remove, removeComment, removeData, removeForced, removeOrphanComment, replace, setAsParentNodeOf, setAsParentNodeOf, setBlockComment, setComment, setData, setLineComment, setParentNode, setParsed, setRange, setTokenRange, stream, stream, toString, toString, tryAddImportToParentCompilationUnit, unregister, walk, walk, walk

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface com.github.javaparser.ast.nodeTypes.NodeWithType

getTypeAsString, setType, setType, tryAddImportToParentCompilationUnit

Methods inherited from interface com.github.javaparser.ast.nodeTypes.NodeWithExpression

setExpression

Methods inherited from interface com.github.javaparser.HasParentNode

findAncestor, findAncestor, findAncestor, hasParentNode, isDescendantOf

Methods inherited from interface com.github.javaparser.ast.nodeTypes.NodeWithRange

containsWithin, containsWithinRange, getBegin, getEnd, hasRange

Constructor Detail

InstanceOfExpr

public InstanceOfExpr()

InstanceOfExpr

public InstanceOfExpr(Expression expression,
                      ReferenceType type)

InstanceOfExpr

public InstanceOfExpr(Expression expression,
                      ReferenceType type,
                      PatternExpr pattern)

InstanceOfExpr

public InstanceOfExpr(TokenRange tokenRange,
                      Expression expression,
                      ReferenceType type,
                      PatternExpr pattern)

This constructor is used by the parser and is considered private.

Method Detail

getName

public Optional<SimpleName> getName()

Helper method which, if this is an expression with a type pattern, returns the identifier/name.

For example:
obj instanceof String stringName

In this example, getName() returns stringName

accept

public <R,A> R accept(GenericVisitor<R,A> v,
                      A arg)

Description copied from interface: Visitable

Accept method for visitor support.

Specified by:

accept in interface Visitable

Type Parameters:

R - the type of the return value of the visitor

A - the type the user argument passed to the visitor

Parameters:

v - the visitor implementation

arg - the argument passed to the visitor (of type A)

Returns:

the result of the visit (of type R)

accept

public <A> void accept(VoidVisitor<A> v,
                       A arg)

Description copied from interface: Visitable

Accept method for visitor support.

Specified by:

accept in interface Visitable

Type Parameters:

A - the type the argument passed for the visitor

Parameters:

v - the visitor implementation

arg - any value relevant for the visitor (of type A)

asInstanceOfExpr

public InstanceOfExpr asInstanceOfExpr()

Overrides:

asInstanceOfExpr in class Expression

clone

public InstanceOfExpr clone()

Overrides:

clone in class Expression

getExpression

public Expression getExpression()

Specified by:

getExpression in interface NodeWithExpression<InstanceOfExpr>

getMetaModel

public InstanceOfExprMetaModel getMetaModel()

Overrides:

getMetaModel in class Expression

Returns:

get JavaParser specific node introspection information.

getPattern

public Optional<PatternExpr> getPattern()

getType

public ReferenceType getType()

Description copied from interface: NodeWithType

Gets the type

Specified by:

getType in interface NodeWithType<InstanceOfExpr,ReferenceType>

Returns:

the type

ifInstanceOfExpr

public void ifInstanceOfExpr(Consumer<InstanceOfExpr> action)

Overrides:

ifInstanceOfExpr in class Expression

isInstanceOfExpr

public boolean isInstanceOfExpr()

Overrides:

isInstanceOfExpr in class Expression

remove

public boolean remove(Node node)

Overrides:

remove in class Node

removePattern

public InstanceOfExpr removePattern()

replace

public boolean replace(Node node,
                       Node replacementNode)

Overrides:

replace in class Node

setExpression

public InstanceOfExpr setExpression(Expression expression)

Specified by:

setExpression in interface NodeWithExpression<InstanceOfExpr>

setPattern

public InstanceOfExpr setPattern(PatternExpr pattern)

setType

public InstanceOfExpr setType(ReferenceType type)

Description copied from interface: NodeWithType

Sets the type

Specified by:

setType in interface NodeWithType<InstanceOfExpr,ReferenceType>

Parameters:

type - the type

Returns:

this

toInstanceOfExpr

public Optional<InstanceOfExpr> toInstanceOfExpr()

Overrides:

toInstanceOfExpr in class Expression