java.lang.Object
- com.puppycrawl.tools.checkstyle.AbstractAutomaticBean
- - com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter
  - - com.puppycrawl.tools.checkstyle.api.AbstractCheck
    - - com.puppycrawl.tools.checkstyle.checks.coding.UnusedLocalVariableCheck

All Implemented Interfaces:

Configurable, Contextualizable
```
public class UnusedLocalVariableCheck
extends AbstractCheck
```
Checks that a local variable is declared and/or assigned, but not used. Doesn't support pattern variables yet. Doesn't check array components as array components are classified as different kind of variables by JLS.
- Property allowUnnamedVariables - Allow variables named with a single underscore (known as unnamed variables in Java 21+). Type is boolean. Default value is true.
Parent is com.puppycrawl.tools.checkstyle.TreeWalker

Violation Message Keys:
- unused.local.var
- unused.named.local.var
Since:

9.3

Nested Class Summary

Nested Classes
Modifier and Type	Class	Description
`private static class`	`UnusedLocalVariableCheck.TypeDeclDesc`	Maintains information about the type declaration.
`private static class`	`UnusedLocalVariableCheck.VariableDesc`	Maintains information about the variable.

Nested classes/interfaces inherited from class com.puppycrawl.tools.checkstyle.AbstractAutomaticBean
AbstractAutomaticBean.OutputStreamOptions

Field Summary

Fields
Modifier and Type	Field	Description
`private boolean`	`allowUnnamedVariables`	Allow variables named with a single underscore (known as unnamed variables in Java 21+).
`private Map<DetailAST,UnusedLocalVariableCheck.TypeDeclDesc>`	`anonInnerAstToTypeDeclDesc`	Maps local anonymous inner class to the TypeDeclDesc object containing it.
`private Set<DetailAST>`	`anonInnerClassHolders`	Set of tokens of type `ANONYMOUS_CLASS_PARENT_TOKENS` and `TokenTypes.LAMBDA` in some cases.
`private static int[]`	`ANONYMOUS_CLASS_PARENT_TOKENS`	An array of blocks in which local anon inner classes can exist.
`private int`	`depth`	Depth at which a type declaration is nested, 0 for top level type declarations.
`private static int[]`	`INCREMENT_AND_DECREMENT_TOKENS`	An array of increment and decrement tokens.
`private static int[]`	`INCREMENT_DECREMENT_VARIABLE_USAGE_TYPES`	An array of token types that indicate a variable is being used within an expression involving increment or decrement operators, or within a switch statement.
`static String`	`MSG_UNUSED_LOCAL_VARIABLE`	A key is pointing to the warning message text in "messages.properties" file.
`static String`	`MSG_UNUSED_NAMED_LOCAL_VARIABLE`	A key is pointing to the warning message text in "messages.properties" file.
`private static String`	`PACKAGE_SEPARATOR`	Package separator.
`private String`	`packageName`	Name of the package.
`private static int[]`	`SCOPES`	An array of scope tokens.
`private Deque<UnusedLocalVariableCheck.TypeDeclDesc>`	`typeDeclarations`	Keeps track of all the type declarations present in the file.
`private Map<DetailAST,UnusedLocalVariableCheck.TypeDeclDesc>`	`typeDeclAstToTypeDeclDesc`	Maps type declaration ast to their respective TypeDeclDesc objects.
`private static int[]`	`UNACCEPTABLE_CHILD_OF_DOT`	An array of unacceptable children of ast of type `TokenTypes.DOT`.
`private static int[]`	`UNACCEPTABLE_PARENT_OF_IDENT`	An array of unacceptable parent of ast of type `TokenTypes.IDENT`.
`private Deque<UnusedLocalVariableCheck.VariableDesc>`	`variables`	Keeps tracks of the variables declared in file.

Constructor Summary

Constructors
Constructor Description

UnusedLocalVariableCheck()

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`private void`	`addInstanceOrClassVar(DetailAST varDefAst)`	Add instance variables and class variables to the `UnusedLocalVariableCheck.TypeDeclDesc.instanceAndClassVarStack`.
`private static void`	`addLocalVariables(DetailAST varDefAst, Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)`	Add local variables to the `variablesStack` stack.
`void`	`beginTree(DetailAST root)`	Called before the starting to process a tree.
`private static void`	`checkIdentifierAst(DetailAST identAst, Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)`	Checks the identifier ast.
`private void`	`customLeaveToken(DetailAST ast, Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)`	Leave all ast nodes under `anonInnerClassHolders` once again.
`private void`	`customVisitToken(DetailAST ast, Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)`	Visit all ast nodes under `anonInnerClassHolders` once again.
`private static DetailAST`	`findScopeOfVariable(DetailAST variableDef)`	Find the scope of variable.
`int[]`	`getAcceptableTokens()`	The configurable token set.
`private static DetailAST`	`getBlockContainingLocalAnonInnerClass(DetailAST literalNewAst)`	Get the block containing local anon inner class.
`int[]`	`getDefaultTokens()`	Returns the default token a check is interested in.
`private String`	`getQualifiedTypeDeclarationName(DetailAST typeDeclAst)`	Get qualified type declaration name from type ast.
`int[]`	`getRequiredTokens()`	The tokens that this check must be registered for.
`private UnusedLocalVariableCheck.TypeDeclDesc`	`getSuperClassOfAnonInnerClass(DetailAST literalNewAst)`	Get the `UnusedLocalVariableCheck.TypeDeclDesc` of the super class of anonymous inner class.
`private static UnusedLocalVariableCheck.TypeDeclDesc`	`getTheNearestClass(String outerTypeDeclName, List<UnusedLocalVariableCheck.TypeDeclDesc> typeDeclWithSameName)`	For all type declarations with the same name as the superclass, gets the nearest type declaration.
`private static int`	`getTypeDeclarationNameMatchingCountDiff(String outerTypeDeclName, UnusedLocalVariableCheck.TypeDeclDesc firstTypeDecl, UnusedLocalVariableCheck.TypeDeclDesc secondTypeDecl)`	Get the difference between type declaration name matching count.
`private boolean`	`hasSameNameAsSuperClass(String superClassName, UnusedLocalVariableCheck.TypeDeclDesc typeDeclDesc)`	Whether the qualified name of `typeDeclDesc` matches the super class name.
`private static boolean`	`isIncrementOrDecrementVariableUsed(DetailAST exprAst)`	A variable with increment or decrement operator is considered used if it is used as an argument or as an array index or for assigning value to a variable.
`private static boolean`	`isInsideLocalAnonInnerClass(DetailAST literalNewAst)`	Whether ast node of type `TokenTypes.LITERAL_NEW` is a part of a local anonymous inner class.
`private static boolean`	`isLeftHandSideValue(DetailAST identAst)`	Checks whether the ast of type `TokenTypes.IDENT` is used as left-hand side value.
`private static boolean`	`isNonLocalTypeDeclaration(DetailAST typeDeclAst)`	Whether a type declaration is non-local.
`private static boolean`	`isPrivateInstanceVariable(DetailAST varDefAst)`	Whether instance variable or class variable have private access modifier.
`private static boolean`	`isStandAloneIncrementOrDecrement(DetailAST identAst)`	Checks whether the ast of type `TokenTypes.IDENT` is used as an operand of a stand-alone increment or decrement.
`private void`	`iterateOverBlockContainingLocalAnonInnerClass(DetailAST ast, Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)`	Iterate over all the ast nodes present under `ast`.
`private void`	`leaveCompilationUnit()`	We process all the blocks containing local anonymous inner classes separately after processing all the other nodes.
`void`	`leaveToken(DetailAST ast)`	Called after all the child nodes have been process.
`private void`	`logViolations(DetailAST scopeAst, Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)`	Traverse `variablesStack` stack and log the violations.
`private void`	`modifyVariablesStack(UnusedLocalVariableCheck.TypeDeclDesc obtainedClass, Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack, DetailAST literalNewAst)`	Add non-private instance and class variables of the super class of the anonymous class to the variables stack.
`void`	`setAllowUnnamedVariables(boolean allowUnnamedVariables)`	Setter to allow variables named with a single underscore (known as unnamed variables in Java 21+).
`private static boolean`	`shouldCheckIdentTokenNestedUnderDot(DetailAST dotAst)`	Whether to check identifier token nested under dotAst.
`private boolean`	`skipUnnamedVariables(DetailAST varDefAst)`	Check for skip current `TokenTypes.VARIABLE_DEF` due to allowUnnamedVariable option.
`private List<UnusedLocalVariableCheck.TypeDeclDesc>`	`typeDeclWithSameName(String superClassName)`	Checks if there is a type declaration with same name as the super class.
`private static void`	`visitDotToken(DetailAST dotAst, Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)`	Visit ast of type `TokenTypes.DOT`.
`private static void`	`visitIdentToken(DetailAST identAst, Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)`	Visit ast of type `TokenTypes.IDENT`.
`private void`	`visitLocalAnonInnerClass(DetailAST literalNewAst)`	Visit the local anon inner class.
`private void`	`visitNonLocalTypeDeclarationToken(DetailAST typeDeclAst)`	Visit the non-local type declaration token.
`void`	`visitToken(DetailAST ast)`	Called to process a token.
`private void`	`visitVariableDefToken(DetailAST varDefAst)`	Visit ast of type `TokenTypes.VARIABLE_DEF`.

Methods inherited from class com.puppycrawl.tools.checkstyle.api.AbstractCheck
clearViolations, destroy, finishTree, getFileContents, getFilePath, getLine, getLineCodePoints, getLines, getTabWidth, getTokenNames, getViolations, init, isCommentNodesRequired, log, log, log, setFileContents, setTabWidth, setTokens

Methods inherited from class com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter
finishLocalSetup, getCustomMessages, getId, getMessageBundle, getSeverity, getSeverityLevel, setId, setSeverity

Methods inherited from class com.puppycrawl.tools.checkstyle.AbstractAutomaticBean
configure, contextualize, getConfiguration, setupChild

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - MSG_UNUSED_LOCAL_VARIABLE
```
public static final String MSG_UNUSED_LOCAL_VARIABLE
```
    A key is pointing to the warning message text in "messages.properties" file.
    
    See Also:
    
    Constant Field Values
  - MSG_UNUSED_NAMED_LOCAL_VARIABLE
```
public static final String MSG_UNUSED_NAMED_LOCAL_VARIABLE
```
    A key is pointing to the warning message text in "messages.properties" file.
    
    See Also:
    
    Constant Field Values
  - INCREMENT_AND_DECREMENT_TOKENS
```
private static final int[] INCREMENT_AND_DECREMENT_TOKENS
```
    An array of increment and decrement tokens.
  - SCOPES
```
private static final int[] SCOPES
```
    An array of scope tokens.
  - UNACCEPTABLE_CHILD_OF_DOT
```
private static final int[] UNACCEPTABLE_CHILD_OF_DOT
```
    An array of unacceptable children of ast of type TokenTypes.DOT.
  - UNACCEPTABLE_PARENT_OF_IDENT
```
private static final int[] UNACCEPTABLE_PARENT_OF_IDENT
```
    An array of unacceptable parent of ast of type TokenTypes.IDENT.
  - ANONYMOUS_CLASS_PARENT_TOKENS
```
private static final int[] ANONYMOUS_CLASS_PARENT_TOKENS
```
    An array of blocks in which local anon inner classes can exist.
  - INCREMENT_DECREMENT_VARIABLE_USAGE_TYPES
```
private static final int[] INCREMENT_DECREMENT_VARIABLE_USAGE_TYPES
```
    An array of token types that indicate a variable is being used within an expression involving increment or decrement operators, or within a switch statement. When a token of one of these types is the parent of an expression, it indicates that the variable associated with the increment or decrement operation is being used. Ex:- TokenTypes.LITERAL_SWITCH: Indicates a switch statement. Variables used within the switch expression are considered to be used
  - PACKAGE_SEPARATOR
```
private static final String PACKAGE_SEPARATOR
```
    Package separator.
    
    See Also:
    
    Constant Field Values
  - variables
```
private final Deque<UnusedLocalVariableCheck.VariableDesc> variables
```
    Keeps tracks of the variables declared in file.
  - typeDeclarations
```
private final Deque<UnusedLocalVariableCheck.TypeDeclDesc> typeDeclarations
```
    Keeps track of all the type declarations present in the file. Pops the type out of the stack while leaving the type in visitor pattern.
  - typeDeclAstToTypeDeclDesc
```
private final Map<DetailAST,UnusedLocalVariableCheck.TypeDeclDesc> typeDeclAstToTypeDeclDesc
```
    Maps type declaration ast to their respective TypeDeclDesc objects.
  - anonInnerAstToTypeDeclDesc
```
private final Map<DetailAST,UnusedLocalVariableCheck.TypeDeclDesc> anonInnerAstToTypeDeclDesc
```
    Maps local anonymous inner class to the TypeDeclDesc object containing it.
  - anonInnerClassHolders
```
private final Set<DetailAST> anonInnerClassHolders
```
    Set of tokens of type ANONYMOUS_CLASS_PARENT_TOKENS and TokenTypes.LAMBDA in some cases.
  - allowUnnamedVariables
```
private boolean allowUnnamedVariables
```
    Allow variables named with a single underscore (known as unnamed variables in Java 21+).
  - packageName
```
private String packageName
```
    Name of the package.
  - depth
```
private int depth
```
    Depth at which a type declaration is nested, 0 for top level type declarations.
- Constructor Detail
  - UnusedLocalVariableCheck
```
public UnusedLocalVariableCheck()
```
- Method Detail
  - setAllowUnnamedVariables
```
public void setAllowUnnamedVariables(boolean allowUnnamedVariables)
```
    Setter to allow variables named with a single underscore (known as unnamed variables in Java 21+).
    
    Parameters:
    
    allowUnnamedVariables - true or false.
    
    Since:
    
    10.18.0
  - getDefaultTokens
```
public int[] getDefaultTokens()
```
    Description copied from class: AbstractCheck
    
    Returns the default token a check is interested in. Only used if the configuration for a check does not define the tokens.
    
    Specified by:
    
    getDefaultTokens in class AbstractCheck
    
    Returns:
    
    the default tokens
    
    See Also:
    
    TokenTypes
  - getAcceptableTokens
```
public int[] getAcceptableTokens()
```
    Description copied from class: AbstractCheck
    
    The configurable token set. Used to protect Checks against malicious users who specify an unacceptable token set in the configuration file. The default implementation returns the check's default tokens.
    
    Specified by:
    
    getAcceptableTokens in class AbstractCheck
    
    Returns:
    
    the token set this check is designed for.
    
    See Also:
    
    TokenTypes
  - getRequiredTokens
```
public int[] getRequiredTokens()
```
    Description copied from class: AbstractCheck
    
    The tokens that this check must be registered for.
    
    Specified by:
    
    getRequiredTokens in class AbstractCheck
    
    Returns:
    
    the token set this must be registered for.
    
    See Also:
    
    TokenTypes
  - beginTree
```
public void beginTree(DetailAST root)
```
    Description copied from class: AbstractCheck
    
    Called before the starting to process a tree. Ideal place to initialize information that is to be collected whilst processing a tree.
    
    Overrides:
    
    beginTree in class AbstractCheck
    
    Parameters:
    
    root - the root of the tree
  - visitToken
```
public void visitToken(DetailAST ast)
```
    Description copied from class: AbstractCheck
    
    Called to process a token.
    
    Overrides:
    
    visitToken in class AbstractCheck
    
    Parameters:
    
    ast - the token to process
  - leaveToken
```
public void leaveToken(DetailAST ast)
```
    Description copied from class: AbstractCheck
    
    Called after all the child nodes have been process.
    
    Overrides:
    
    leaveToken in class AbstractCheck
    
    Parameters:
    
    ast - the token leaving
  - visitDotToken
```
private static void visitDotToken(DetailAST dotAst,
                                  Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)
```
    Visit ast of type TokenTypes.DOT.
    
    Parameters:
    
    dotAst - dotAst
    
    variablesStack - stack of all the relevant variables in the scope
  - visitVariableDefToken
```
private void visitVariableDefToken(DetailAST varDefAst)
```
    Visit ast of type TokenTypes.VARIABLE_DEF.
    
    Parameters:
    
    varDefAst - varDefAst
  - visitIdentToken
```
private static void visitIdentToken(DetailAST identAst,
                                    Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)
```
    Visit ast of type TokenTypes.IDENT.
    
    Parameters:
    
    identAst - identAst
    
    variablesStack - stack of all the relevant variables in the scope
  - visitNonLocalTypeDeclarationToken
```
private void visitNonLocalTypeDeclarationToken(DetailAST typeDeclAst)
```
    Visit the non-local type declaration token.
    
    Parameters:
    
    typeDeclAst - type declaration ast
  - visitLocalAnonInnerClass
```
private void visitLocalAnonInnerClass(DetailAST literalNewAst)
```
    Visit the local anon inner class.
    
    Parameters:
    
    literalNewAst - literalNewAst
  - skipUnnamedVariables
```
private boolean skipUnnamedVariables(DetailAST varDefAst)
```
    Check for skip current TokenTypes.VARIABLE_DEF due to allowUnnamedVariable option.
    
    Parameters:
    
    varDefAst - varDefAst variable to check
    
    Returns:
    
    true if the current variable should be skipped.
  - isInsideLocalAnonInnerClass
```
private static boolean isInsideLocalAnonInnerClass(DetailAST literalNewAst)
```
    Whether ast node of type TokenTypes.LITERAL_NEW is a part of a local anonymous inner class.
    
    Parameters:
    
    literalNewAst - ast node of type TokenTypes.LITERAL_NEW
    
    Returns:
    
    true if variableDefAst is an instance variable in local anonymous inner class
  - logViolations
```
private void logViolations(DetailAST scopeAst,
                           Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)
```
    Traverse variablesStack stack and log the violations.
    
    Parameters:
    
    scopeAst - ast node of type SCOPES
    
    variablesStack - stack of all the relevant variables in the scope
  - leaveCompilationUnit
```
private void leaveCompilationUnit()
```
    We process all the blocks containing local anonymous inner classes separately after processing all the other nodes. This is being done due to the fact the instance variables of local anon inner classes can cast a shadow on local variables.
  - isNonLocalTypeDeclaration
```
private static boolean isNonLocalTypeDeclaration(DetailAST typeDeclAst)
```
    Whether a type declaration is non-local. Annotated interfaces are always non-local.
    
    Parameters:
    
    typeDeclAst - type declaration ast
    
    Returns:
    
    true if type declaration is non-local
  - getBlockContainingLocalAnonInnerClass
```
private static DetailAST getBlockContainingLocalAnonInnerClass(DetailAST literalNewAst)
```
    Get the block containing local anon inner class.
    
    Parameters:
    
    literalNewAst - ast node of type TokenTypes.LITERAL_NEW
    
    Returns:
    
    the block containing local anon inner class
  - addLocalVariables
```
private static void addLocalVariables(DetailAST varDefAst,
                                      Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)
```
    Add local variables to the variablesStack stack. Also adds the instance variables defined in a local anonymous inner class.
    
    Parameters:
    
    varDefAst - ast node of type TokenTypes.VARIABLE_DEF
    
    variablesStack - stack of all the relevant variables in the scope
  - addInstanceOrClassVar
```
private void addInstanceOrClassVar(DetailAST varDefAst)
```
    Add instance variables and class variables to the UnusedLocalVariableCheck.TypeDeclDesc.instanceAndClassVarStack.
    
    Parameters:
    
    varDefAst - ast node of type TokenTypes.VARIABLE_DEF
  - isPrivateInstanceVariable
```
private static boolean isPrivateInstanceVariable(DetailAST varDefAst)
```
    Whether instance variable or class variable have private access modifier.
    
    Parameters:
    
    varDefAst - ast node of type TokenTypes.VARIABLE_DEF
    
    Returns:
    
    true if instance variable or class variable have private access modifier
  - getSuperClassOfAnonInnerClass
```
private UnusedLocalVariableCheck.TypeDeclDesc getSuperClassOfAnonInnerClass(DetailAST literalNewAst)
```
    Get the UnusedLocalVariableCheck.TypeDeclDesc of the super class of anonymous inner class.
    
    Parameters:
    
    literalNewAst - ast node of type TokenTypes.LITERAL_NEW
    
    Returns:
    
    UnusedLocalVariableCheck.TypeDeclDesc of the super class of anonymous inner class
  - modifyVariablesStack
```
private void modifyVariablesStack(UnusedLocalVariableCheck.TypeDeclDesc obtainedClass,
                                  Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack,
                                  DetailAST literalNewAst)
```
    Add non-private instance and class variables of the super class of the anonymous class to the variables stack.
    
    Parameters:
    
    obtainedClass - super class of the anon inner class
    
    variablesStack - stack of all the relevant variables in the scope
    
    literalNewAst - ast node of type TokenTypes.LITERAL_NEW
  - typeDeclWithSameName
```
private List<UnusedLocalVariableCheck.TypeDeclDesc> typeDeclWithSameName(String superClassName)
```
    Checks if there is a type declaration with same name as the super class.
    
    Parameters:
    
    superClassName - name of the super class
    
    Returns:
    
    list if there is another type declaration with same name.
  - hasSameNameAsSuperClass
```
private boolean hasSameNameAsSuperClass(String superClassName,
                                        UnusedLocalVariableCheck.TypeDeclDesc typeDeclDesc)
```
    Whether the qualified name of typeDeclDesc matches the super class name.
    
    Parameters:
    
    superClassName - name of the super class
    
    typeDeclDesc - type declaration description
    
    Returns:
    
    true if the qualified name of typeDeclDesc matches the super class name
  - getTheNearestClass
```
private static UnusedLocalVariableCheck.TypeDeclDesc getTheNearestClass(String outerTypeDeclName,
                                                                        List<UnusedLocalVariableCheck.TypeDeclDesc> typeDeclWithSameName)
```
    For all type declarations with the same name as the superclass, gets the nearest type declaration.
    
    Parameters:
    
    outerTypeDeclName - outer type declaration of anonymous inner class
    
    typeDeclWithSameName - typeDeclarations which have the same name as the super class
    
    Returns:
    
    the nearest class
  - getTypeDeclarationNameMatchingCountDiff
```
private static int getTypeDeclarationNameMatchingCountDiff(String outerTypeDeclName,
                                                           UnusedLocalVariableCheck.TypeDeclDesc firstTypeDecl,
                                                           UnusedLocalVariableCheck.TypeDeclDesc secondTypeDecl)
```
    Get the difference between type declaration name matching count. If the difference between them is zero, then their depth is compared to obtain the result.
    
    Parameters:
    
    outerTypeDeclName - outer type declaration of anonymous inner class
    
    firstTypeDecl - first input type declaration
    
    secondTypeDecl - second input type declaration
    
    Returns:
    
    difference between type declaration name matching count
  - getQualifiedTypeDeclarationName
```
private String getQualifiedTypeDeclarationName(DetailAST typeDeclAst)
```
    Get qualified type declaration name from type ast.
    
    Parameters:
    
    typeDeclAst - type declaration ast
    
    Returns:
    
    qualified name of type declaration
  - iterateOverBlockContainingLocalAnonInnerClass
```
private void iterateOverBlockContainingLocalAnonInnerClass(DetailAST ast,
                                                           Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)
```
    Iterate over all the ast nodes present under ast.
    
    Parameters:
    
    ast - ast
    
    variablesStack - stack of all the relevant variables in the scope
  - customVisitToken
```
private void customVisitToken(DetailAST ast,
                              Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)
```
    Visit all ast nodes under anonInnerClassHolders once again.
    
    Parameters:
    
    ast - ast
    
    variablesStack - stack of all the relevant variables in the scope
  - customLeaveToken
```
private void customLeaveToken(DetailAST ast,
                              Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)
```
    Leave all ast nodes under anonInnerClassHolders once again.
    
    Parameters:
    
    ast - ast
    
    variablesStack - stack of all the relevant variables in the scope
  - shouldCheckIdentTokenNestedUnderDot
```
private static boolean shouldCheckIdentTokenNestedUnderDot(DetailAST dotAst)
```
    Whether to check identifier token nested under dotAst.
    
    Parameters:
    
    dotAst - dotAst
    
    Returns:
    
    true if ident nested under dotAst should be checked
  - checkIdentifierAst
```
private static void checkIdentifierAst(DetailAST identAst,
                                       Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)
```
    Checks the identifier ast.
    
    Parameters:
    
    identAst - ast of type TokenTypes.IDENT
    
    variablesStack - stack of all the relevant variables in the scope
  - findScopeOfVariable
```
private static DetailAST findScopeOfVariable(DetailAST variableDef)
```
    Find the scope of variable.
    
    Parameters:
    
    variableDef - ast of type TokenTypes.VARIABLE_DEF
    
    Returns:
    
    scope of variableDef
  - isLeftHandSideValue
```
private static boolean isLeftHandSideValue(DetailAST identAst)
```
    Checks whether the ast of type TokenTypes.IDENT is used as left-hand side value. An identifier is being used as a left-hand side value if it is used as the left operand of an assignment or as an operand of a stand-alone increment or decrement.
    
    Parameters:
    
    identAst - ast of type TokenTypes.IDENT
    
    Returns:
    
    true if identAst is used as a left-hand side value
  - isStandAloneIncrementOrDecrement
```
private static boolean isStandAloneIncrementOrDecrement(DetailAST identAst)
```
    Checks whether the ast of type TokenTypes.IDENT is used as an operand of a stand-alone increment or decrement.
    
    Parameters:
    
    identAst - ast of type TokenTypes.IDENT
    
    Returns:
    
    true if identAst is used as an operand of stand-alone increment or decrement
  - isIncrementOrDecrementVariableUsed
```
private static boolean isIncrementOrDecrementVariableUsed(DetailAST exprAst)
```
    A variable with increment or decrement operator is considered used if it is used as an argument or as an array index or for assigning value to a variable.
    
    Parameters:
    
    exprAst - ast of type TokenTypes.EXPR
    
    Returns:
    
    true if variable nested in exprAst is used

Class UnusedLocalVariableCheck

Nested Class Summary

Nested classes/interfaces inherited from class com.puppycrawl.tools.checkstyle.AbstractAutomaticBean

Field Summary

Constructor Summary

Method Summary

Methods inherited from class com.puppycrawl.tools.checkstyle.api.AbstractCheck

Methods inherited from class com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter

Methods inherited from class com.puppycrawl.tools.checkstyle.AbstractAutomaticBean

Methods inherited from class java.lang.Object

Field Detail

MSG_UNUSED_LOCAL_VARIABLE

MSG_UNUSED_NAMED_LOCAL_VARIABLE

INCREMENT_AND_DECREMENT_TOKENS

SCOPES

UNACCEPTABLE_CHILD_OF_DOT

UNACCEPTABLE_PARENT_OF_IDENT

ANONYMOUS_CLASS_PARENT_TOKENS

INCREMENT_DECREMENT_VARIABLE_USAGE_TYPES

PACKAGE_SEPARATOR

variables

typeDeclarations

typeDeclAstToTypeDeclDesc

anonInnerAstToTypeDeclDesc

anonInnerClassHolders

allowUnnamedVariables

packageName

depth

Constructor Detail

UnusedLocalVariableCheck

Method Detail

setAllowUnnamedVariables

getDefaultTokens

getAcceptableTokens

getRequiredTokens

beginTree

visitToken

leaveToken

visitDotToken

visitVariableDefToken

visitIdentToken

visitNonLocalTypeDeclarationToken

visitLocalAnonInnerClass

skipUnnamedVariables

isInsideLocalAnonInnerClass

logViolations

leaveCompilationUnit

isNonLocalTypeDeclaration

getBlockContainingLocalAnonInnerClass

addLocalVariables

addInstanceOrClassVar

isPrivateInstanceVariable

getSuperClassOfAnonInnerClass

modifyVariablesStack

typeDeclWithSameName

hasSameNameAsSuperClass

getTheNearestClass

getTypeDeclarationNameMatchingCountDiff

getQualifiedTypeDeclarationName

iterateOverBlockContainingLocalAnonInnerClass

customVisitToken

customLeaveToken

shouldCheckIdentTokenNestedUnderDot

checkIdentifierAst

findScopeOfVariable

isLeftHandSideValue

isStandAloneIncrementOrDecrement

isIncrementOrDecrementVariableUsed