Package com.puppycrawl.tools.checkstyle.checks.coding

Class ModifiedControlVariableCheck

  • All Implemented Interfaces:
    Configurable, Contextualizable
    public final class ModifiedControlVariableCheck
extends AbstractCheck

    Checks that for loop control variables are not modified inside the for block. An example is: 

     for (int i = 0; i < 1; i++) {
   i++; //violation
 }

    Rationale: If the control variable is modified inside the loop body, the program flow becomes more difficult to follow. See FOR statement specification for more details.

    Such loop would be suppressed: 

     for (int i = 0; i < 10;) {
   i++;
 }
    • Property skipEnhancedForLoopVariable - Control whether to check enhanced for-loop variable. Type is boolean. Default value is false.

    To configure the check: 

     <module name="ModifiedControlVariable"/>

    By default, This Check validates Enhanced For-Loop.

    Option 'skipEnhancedForLoopVariable' could be used to skip check of variable from Enhanced For Loop.

    An example of how to configure the check so that it skips enhanced For Loop Variable is: 

     <module name="ModifiedControlVariable">
   <property name="skipEnhancedForLoopVariable" value="true"/>
 </module>

    Example:

     for (String line: lines) {
   line = line.trim();   // it will skip this violation
 }

    Parent is com.puppycrawl.tools.checkstyle.TreeWalker

    Violation Message Keys:

    • modified.control.variable
    Since:
    3.5

    • Field Detail

      • MSG_KEY

        public static final java.lang.String MSG_KEY
        A key is pointing to the warning message text in "messages.properties" file.
        See Also:
        Constant Field Values

    • Constructor Detail

      • ModifiedControlVariableCheck

        public ModifiedControlVariableCheck()

    • Method Detail

      • setSkipEnhancedForLoopVariable

        public void setSkipEnhancedForLoopVariable​(boolean skipEnhancedForLoopVariable)
        Setter to control whether to check enhanced for-loop variable.
        Parameters:
        skipEnhancedForLoopVariable - whether to skip enhanced for-loop variable

      • 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

      • 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

      • 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

      • beginTree

        public void beginTree​(DetailAST rootAST)
        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:
        rootAST - the root of the tree

      • 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