Class LocalVariableNameCheck
- All Implemented Interfaces:
Configurable
,Contextualizable
Checks that local, non-final
variable names conform to a specified pattern.
A catch parameter is considered to be
a local variable.
-
Property
format
- Specifies valid identifiers. Type isjava.util.regex.Pattern
. Default value is"^[a-z][a-zA-Z0-9]*$"
. -
Property
allowOneCharVarInForLoop
- Allow one character variable name in initialization expressions in FOR loop if one char variable name is prohibited byformat
regexp. Type isboolean
. Default value isfalse
.
To configure the check:
<module name="LocalVariableName"/>
Code Example:
class MyClass { void MyMethod() { for (int var = 1; var < 10; var++) {} // OK for (int VAR = 1; VAR < 10; VAR++) {} // violation, name 'VAR' must match // pattern '^[a-z][a-zA-Z0-9]*$' for (int i = 1; i < 10; i++) {} // OK for (int var_1 = 0; var_1 < 10; var_1++) {} // violation, name 'var_1' must match // pattern '^[a-z][a-zA-Z0-9]*$' } }
An example of how to configure the check for names that begin with a lower case letter, followed by letters, digits, and underscores is:
<module name="LocalVariableName"> <property name="format" value="^[a-z](_?[a-zA-Z0-9]+)*$"/> </module>
Code Example:
class MyClass { void MyMethod() { for (int var = 1; var < 10; var++) {} // OK for (int VAR = 1; VAR < 10; VAR++) {} // violation, name 'VAR' must match // pattern '^[a-z](_?[a-zA-Z0-9]+)*$' for (int i = 1; i < 10; i++) {} // OK for (int var_1 = 0; var_1 < 10; var_1++) {} // OK } }
An example of one character variable name in initialization expression(like "i") in FOR loop:
for(int i = 1; i < 10; i++) {} for(int K = 1; K < 10; K++) {} List list = new ArrayList(); for (Object o : list) {} for (Object O : list) {}
An example of how to configure the check to allow one character variable name in initialization expressions in FOR loop, where regexp allows 2 or more chars:
<module name="LocalVariableName"> <property name="format" value="^[a-z][_a-zA-Z0-9]+$"/> <property name="allowOneCharVarInForLoop" value="true"/> </module>
Code Example:
class MyClass { void MyMethod() { int good = 1; int g = 0; // violation for (int v = 1; v < 10; v++) { // OK int a = 1; // violation } for (int V = 1; V < 10; V++) { // OK int I = 1; // violation } List list = new ArrayList(); for (Object o : list) { // OK String a = ""; // violation } for (Object O : list) { // OK String A = ""; // violation } } }
An example of how to configure the check to that all variables have 3 or more chars in name:
<module name="LocalVariableName"> <property name="format" value="^[a-z][_a-zA-Z0-9]{2,}$"/> </module>
Code Example:
class MyClass { void MyMethod() { int goodName = 0; int i = 1; // violation for (int var = 1; var < 10; var++) { //OK int j = 1; // violation } } }
Parent is com.puppycrawl.tools.checkstyle.TreeWalker
Violation Message Keys:
-
name.invalidPattern
- Since:
- 3.0
-
Nested Class Summary
Nested classes/interfaces inherited from class com.puppycrawl.tools.checkstyle.api.AutomaticBean
AutomaticBean.OutputStreamOptions
-
Field Summary
Fields inherited from class com.puppycrawl.tools.checkstyle.checks.naming.AbstractNameCheck
MSG_INVALID_PATTERN
-
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionint[]
The configurable token set.int[]
Returns the default token a check is interested in.int[]
The tokens that this check must be registered for.protected final boolean
mustCheckName
(DetailAST ast) Decides whether the name of an AST should be checked against the format regexp.final void
setAllowOneCharVarInForLoop
(boolean allow) Setter to allow one character variable name in initialization expressions in FOR loop if one char variable name is prohibited byformat
regexp.Methods inherited from class com.puppycrawl.tools.checkstyle.checks.naming.AbstractNameCheck
setFormat, visitToken
Methods inherited from class com.puppycrawl.tools.checkstyle.api.AbstractCheck
beginTree, clearMessages, destroy, finishTree, getFileContents, getLine, getLines, getMessages, getTabWidth, getTokenNames, init, isCommentNodesRequired, leaveToken, 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.api.AutomaticBean
configure, contextualize, getConfiguration, setupChild
-
Constructor Details
-
LocalVariableNameCheck
public LocalVariableNameCheck()Creates a newLocalVariableNameCheck
instance.
-
-
Method Details
-
setAllowOneCharVarInForLoop
public final void setAllowOneCharVarInForLoop(boolean allow) Setter to allow one character variable name in initialization expressions in FOR loop if one char variable name is prohibited byformat
regexp.- Parameters:
allow
- Flag for allowing or not one character name in FOR loop.
-
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 classAbstractCheck
- Returns:
- the default tokens
- See Also:
-
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 classAbstractCheck
- Returns:
- the token set this check is designed for.
- See Also:
-
getRequiredTokens
public int[] getRequiredTokens()Description copied from class:AbstractCheck
The tokens that this check must be registered for.- Specified by:
getRequiredTokens
in classAbstractCheck
- Returns:
- the token set this must be registered for.
- See Also:
-
mustCheckName
Description copied from class:AbstractNameCheck
Decides whether the name of an AST should be checked against the format regexp.- Specified by:
mustCheckName
in classAbstractNameCheck
- Parameters:
ast
- the AST to check.- Returns:
- true if the IDENT subnode of ast should be checked against the format regexp.
-