com.github.sevntu.checkstyle.checks.coding

Class AvoidConstantAsFirstOperandInConditionCheck

java.lang.Object

com.puppycrawl.tools.checkstyle.api.AutomaticBean

com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter

com.puppycrawl.tools.checkstyle.api.AbstractCheck

com.github.sevntu.checkstyle.checks.coding.AvoidConstantAsFirstOperandInConditionCheck

All Implemented Interfaces:

com.puppycrawl.tools.checkstyle.api.Configurable, com.puppycrawl.tools.checkstyle.api.Contextualizable

public class AvoidConstantAsFirstOperandInConditionCheck
extends com.puppycrawl.tools.checkstyle.api.AbstractCheck

If comparing values, C(C++) developers prefer to put the constant first in the equality check, to prevent situations of assignment rather than equality checking.

But in Java, in IF condition it is impossible to use assignment, so that habit become unnecessary and do damage readability of code.

In C(C++), comparison for null is tricky, and it is easy to write "=" instead of "==", and no complication error will be but condition will work in different way

Example: if (null == variable) rather than if (variable == null) because if you forget one (typo mistake) of the equal sign, you end up with if (variable = null) which assigns null to variable and IF always evaluate to true.

Author:

Sergey Burtsev

Field Summary

Fields

Modifier and Type	Field and Description
static String	MSG_KEY A key is pointing to the warning message text in "messages.properties" file.

Constructor Summary

Constructors

Constructor and Description
AvoidConstantAsFirstOperandInConditionCheck()

Method Summary

Modifier and Type	Method and Description
int[]	getAcceptableTokens()
int[]	getDefaultTokens()
int[]	getRequiredTokens()
void	setTargetConstantTypes(String[] targets) Set target constant types.
void	visitToken(com.puppycrawl.tools.checkstyle.api.DetailAST detailAST)

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

beginTree, destroy, finishTree, getClassLoader, getFileContents, getLine, getLines, getTabWidth, getTokenNames, init, isCommentNodesRequired, leaveToken, log, log, setClassLoader, setFileContents, setMessages, setTabWidth, setTokens

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

getCustomMessages, getId, getMessageBundle, getSeverity, getSeverityLevel, log, setId, setSeverity

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

configure, contextualize, finishLocalSetup, getConfiguration, setupChild

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

MSG_KEY

public static final String MSG_KEY

A key is pointing to the warning message text in "messages.properties" file.

See Also:

Constant Field Values

Constructor Detail

AvoidConstantAsFirstOperandInConditionCheck

public AvoidConstantAsFirstOperandInConditionCheck()

Method Detail

setTargetConstantTypes

public void setTargetConstantTypes(String[] targets)

Set target constant types.

Parameters:

targets - target constant types

getDefaultTokens

public int[] getDefaultTokens()

Specified by:

getDefaultTokens in class com.puppycrawl.tools.checkstyle.api.AbstractCheck

getAcceptableTokens

public int[] getAcceptableTokens()

Overrides:

getAcceptableTokens in class com.puppycrawl.tools.checkstyle.api.AbstractCheck

getRequiredTokens

public int[] getRequiredTokens()

Overrides:

getRequiredTokens in class com.puppycrawl.tools.checkstyle.api.AbstractCheck

visitToken

public void visitToken(com.puppycrawl.tools.checkstyle.api.DetailAST detailAST)

Overrides:

visitToken in class com.puppycrawl.tools.checkstyle.api.AbstractCheck