Concept Matrix
247 Misconceptions vs. 58 Concepts

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AbstractClassMustImplementAbstractMethod3⬤⬤⬤
AbstractClassNoImplementation2⬤⬤
AddMemberAtRuntime4⬤⬤⬤⬤
AllClassesHaveDefaultConstructor2⬤⬤
AnyClassException2⬤⬤
ArithmeticPlusPrecedes5⬤⬤⬤⬤⬤
ArrayAccessWithParentheses2⬤⬤
ArrayAllocationWithoutNew2⬤⬤
ArrayBracketCountIsLength2⬤⬤
ArrayElementTypeRepeats2⬤⬤
ArrayElementsUntyped2⬤⬤
ArrayHasLengthMethod3⬤⬤⬤
ArrayInitializerContentsInBrackets2⬤⬤
ArrayLengthCannotBeZero1⬤
ArrayLengthPartOfType2⬤⬤
ArrayListIsArray2⬤⬤
ArrayRankIsLength1⬤
ArrayRankNotPartOfType2⬤⬤
ArraysGrow2⬤⬤
AssignCompares4⬤⬤⬤⬤
AssignmentCopiesObject4⬤⬤⬤⬤
AssignmentNotExpression3⬤⬤⬤
BaseCaseNotNeeded4⬤⬤⬤⬤
BaseCaseSelfRecursive3⬤⬤⬤
CallNotStaticallyChecked4⬤⬤⬤⬤
CallOnPrimitive3⬤⬤⬤
CallRequiresVariable2⬤⬤
CallWithoutFrame3⬤⬤⬤
CallerFrameContainsCalleeFormal5⬤⬤⬤⬤⬤
CannotChainMemberAccesses6⬤⬤⬤⬤⬤⬤
CannotChainMemberToConstructor7⬤⬤⬤⬤⬤⬤⬤
CatchAlwaysExecutes2⬤⬤
CatchProvidesOptions2⬤⬤
ChainedMethodsNotCalledFromOutside4⬤⬤⬤⬤
CharNotNumeric3⬤⬤⬤
ComparisonWithBooleanLiteral4⬤⬤⬤⬤
CompositeExpressionsUntyped2⬤⬤
ConcreteClassMustOverride3⬤⬤⬤
ConcreteClassOnlyImplementClassAbstract4⬤⬤⬤⬤
ConcreteClassOnlyImplementDirectAbstract4⬤⬤⬤⬤
ConcreteClassOnlyImplementInterfaceAbstract4⬤⬤⬤⬤
ConditionalIsSequence2⬤⬤
ConstructorAllocates3⬤⬤⬤
ConstructorParameterIsField3⬤⬤⬤
ConstructorReturnsObject4⬤⬤⬤⬤
ConstructorWithoutNew3⬤⬤⬤
ControlledLocalAccess4⬤⬤⬤⬤
DeferredReturn4⬤⬤⬤⬤
ElsIf2⬤⬤
ElseAlwaysExecutes2⬤⬤
EqualityOperatorComparesObjectsValues6⬤⬤⬤⬤⬤⬤
EqualsComparesReferences6⬤⬤⬤⬤⬤⬤
EvaluationResultsArePrinted2⬤⬤
ExceptionRoot2⬤⬤
ExpressionAssigns3⬤⬤⬤
ExpressionsDynamicallyTyped4⬤⬤⬤⬤
FinalReferenceImpliesImmutability2⬤⬤
ForEachIteratesOverIndices3⬤⬤⬤
ForEachTraversesRecursiveStructure2⬤⬤
ForEachVariableIsElement3⬤⬤⬤
ForIsConditional3⬤⬤⬤
ForVariableScopeBeyondLoop3⬤⬤⬤
FrameIsClassInstance3⬤⬤⬤
IfIsLoop3⬤⬤⬤
IfRequiresElse2⬤⬤
ImmutableRequiresFinalParameters5⬤⬤⬤⬤⬤
ImplicitInterfaceImplementation3⬤⬤⬤
IntegerDivisionToRational2⬤⬤
InterfaceExtendClass3⬤⬤⬤
LargeIntegerLong4⬤⬤⬤⬤
LiteralNoExpression2⬤⬤
LiteralString3⬤⬤⬤
LocalVariablesAutoInitialized3⬤⬤⬤
LoopBodyScopeImpliesLoopLifetime4⬤⬤⬤⬤
LoopTerminatingCondition3⬤⬤⬤
MapToBooleanWithConditionalOperator4⬤⬤⬤⬤
MapToBooleanWithIf3⬤⬤⬤
MethodAsField4⬤⬤⬤⬤
MethodWithoutReturnType2⬤⬤
MethodsWithoutClass2⬤⬤
MultiReferenceVariable3⬤⬤⬤
MultiValueVariable2⬤⬤
MultidimensionalArray1⬤
MultipleSuperclasses2⬤⬤
MustInitializeFieldInConstructor5⬤⬤⬤⬤⬤
NamedTypeParameter3⬤⬤⬤
NestedObjectsImplyNestedClasses2⬤⬤
NestedPackages1⬤
NoAtomicExpression4⬤⬤⬤⬤
NoCallOnStringLiteral4⬤⬤⬤⬤
NoCastIfSameSize4⬤⬤⬤⬤
NoCharEscape2⬤⬤
NoEmptyConstructor1⬤
NoFieldInheritance3⬤⬤⬤
NoFieldlessObjects2⬤⬤
NoFloatLiterals3⬤⬤⬤
NoImplicitWidening1⬤
NoInsideMethodCallInConstructor4⬤⬤⬤⬤
NoJaggedArrays1⬤
NoLocalVariables2⬤⬤
NoLongLiterals3⬤⬤⬤
NoMethodInheritance4⬤⬤⬤⬤
NoReservedWords1⬤
NoShortCircuit5⬤⬤⬤⬤⬤
NoSingleLogicAnd2⬤⬤
NoStringToString3⬤⬤⬤
NullIsObject5⬤⬤⬤⬤⬤
NullPointerExceptionCompileTime1⬤
NumericToBooleanCoercion3⬤⬤⬤
ObjectsMustBeNamed5⬤⬤⬤⬤⬤
OnlyInnermostArrayElements1⬤
OutOfBoundsElementsAreNull2⬤⬤
OutsideInMethodNesting5⬤⬤⬤⬤⬤
ParenthesesOnlyIfArgument3⬤⬤⬤
PreIncrementBeforeLoop3⬤⬤⬤
PrimitiveIsObject3⬤⬤⬤
PrimitiveTypeParameter3⬤⬤⬤
PrimitiveVariablesDynamicallyTyped2⬤⬤
PrivateAccessibleInSubclass4⬤⬤⬤⬤
PrivateFieldsImplyImmutability4⬤⬤⬤⬤
PrivateFromOtherInstance2⬤⬤
PrivateFromStatic3⬤⬤⬤
PrivateMeansFinal3⬤⬤⬤
RationalLiterals2⬤⬤
RecursiveActivationsShareFrame2⬤⬤
RecursiveCallSiteNoReturn2⬤⬤
RecursiveMethodImpliesRecursiveType3⬤⬤⬤
RecursiveMethodNeedsIfElse4⬤⬤⬤⬤
ReferenceIntoStack2⬤⬤
ReferenceToBooleanCoercion3⬤⬤⬤
ReferenceToIntegerConversion3⬤⬤⬤
ReferenceToVariable2⬤⬤
ReferringToRecursiveStructureMakesRecursive2⬤⬤
ReturnCall3⬤⬤⬤
ReturnUnwindsMultipleFrames4⬤⬤⬤⬤
RightToLeftChaining7⬤⬤⬤⬤⬤⬤⬤
RuntimeExceptionChecked2⬤⬤
SingleQuoteString2⬤⬤
StackTraceIsCallHistory3⬤⬤⬤
StaticCallPolymorphic5⬤⬤⬤⬤⬤
StaticDispatch4⬤⬤⬤⬤
StringLengthField3⬤⬤⬤
StringLiteralNoObject2⬤⬤
StringPlusStringifiesExpression3⬤⬤⬤
StringRepetitionOperator3⬤⬤⬤
SubtypeCompatibleWithSupertype4⬤⬤⬤⬤
SuperAlwaysHasParentheses2⬤⬤
SuperNotFirstStatement2⬤⬤
SuperclassObjectAllocated4⬤⬤⬤⬤
SupertypeIncompatibleWithSubtype4⬤⬤⬤⬤
TargetTyping3⬤⬤⬤
ThisAsField5⬤⬤⬤⬤⬤
ThisAssignable6⬤⬤⬤⬤⬤⬤
ThisCanBeNull3⬤⬤⬤
ThisExistsInStaticMethod6⬤⬤⬤⬤⬤⬤
ThisInConstructorIsNull4⬤⬤⬤⬤
ThisNoExpression2⬤⬤
ToStringPrints4⬤⬤⬤⬤
TryCatchMandatory2⬤⬤
TryFinishes2⬤⬤
UndeclaredVariables1⬤
UnqualifiedNamesMustDiffer3⬤⬤⬤
UntypedVariables2⬤⬤
UseOfSelfTypeImpliesRecursiveType8⬤⬤⬤⬤⬤⬤⬤⬤
VariablesHoldExpressions3⬤⬤⬤
VariablesHoldObjects3⬤⬤⬤
VoidMethodNotRecursive3⬤⬤⬤
VoidMethodReturnsValue4⬤⬤⬤⬤
ZeroDigitsCompress1⬤
AccessingInexistentPropertyError5⬤⬤⬤⬤⬤
ArrowFunctionNoImpliedReturn3⬤⬤⬤
ArrowFunctionRequiresFunctionKeyword2⬤⬤
AssignmentCopiesObject4⬤⬤⬤⬤
CallbackParametersInCaller5⬤⬤⬤⬤⬤
CharType2⬤⬤
ClassDefinesType2⬤⬤
ConditionalOperatorNotExpression4⬤⬤⬤⬤
ConstDeclarationCanBeLeftUninitialized2⬤⬤
ConstReferenceImpliesImmutability2⬤⬤
EqualityOperatorComparesObjectsValues5⬤⬤⬤⬤⬤
EqualityOperatorComparesOnlyTypes4⬤⬤⬤⬤
FunctionAsValueWithParentheses3⬤⬤⬤
FunctionOverloading3⬤⬤⬤
FunctionsCannotBeImmediatelyInvoked3⬤⬤⬤
FunctionsMustBeNamed3⬤⬤⬤
IdentifierAsStringInBracketNotation4⬤⬤⬤⬤
MandatoryAssignment3⬤⬤⬤
MapInPlace2⬤⬤
NoAtomicExpression4⬤⬤⬤⬤
NoBracketNotationForObjects2⬤⬤
NoFunctionCallsChaining4⬤⬤⬤⬤
NoGlobalObject2⬤⬤
NoReturnValue3⬤⬤⬤
NullAndUndefinedAreTheSame5⬤⬤⬤⬤⬤
NullIsObject5⬤⬤⬤⬤⬤
NumberOfParametersMatchArguments4⬤⬤⬤⬤
ObjectAsParameterIsCopied4⬤⬤⬤⬤
PrototypesAreClasses2⬤⬤
StringRepetitionOperator3⬤⬤⬤
ThisAssignable6⬤⬤⬤⬤⬤⬤
TypeofArrayIsArray2⬤⬤
TypeofNullIsNull2⬤⬤
AssignCompares4⬤⬤⬤⬤
AssignmentCopiesObject6⬤⬤⬤⬤⬤⬤
CannotChainAttributeAccesses6⬤⬤⬤⬤⬤⬤
CannotChainAttributeToObjectInstantiation7⬤⬤⬤⬤⬤⬤⬤
ComparisonWithBoolLiteral6⬤⬤⬤⬤⬤⬤
ConditionalIsSequence2⬤⬤
DeferredReturn4⬤⬤⬤⬤
IfIsLoop3⬤⬤⬤
InitCreates3⬤⬤⬤
InitReturnsObject4⬤⬤⬤⬤
MapToBooleanWithIf4⬤⬤⬤⬤
MapToBooleanWithTernaryOperator4⬤⬤⬤⬤
MultipleValuesReturn3⬤⬤⬤
NoAtomicExpression4⬤⬤⬤⬤
NoEmptyInit1⬤
NoReservedWords1⬤
NoSequenceRepetition4⬤⬤⬤⬤
NoShortCircuit5⬤⬤⬤⬤⬤
NoSingleLogicAnd3⬤⬤⬤
ObjectsMustBeNamed6⬤⬤⬤⬤⬤⬤
OutsideInFunctionNesting5⬤⬤⬤⬤⬤
ParenthesesOnlyIfArgument3⬤⬤⬤
PlusConcatenatesNumbers5⬤⬤⬤⬤⬤
RecursiveFunctionNeedsIfElse3⬤⬤⬤
ReturnCall4⬤⬤⬤⬤
ReturnUnwindsMultipleFrames4⬤⬤⬤⬤
RightToLeftChaining7⬤⬤⬤⬤⬤⬤⬤
SelfAssignable6⬤⬤⬤⬤⬤⬤
SelfNoExpression2⬤⬤
StringLiteralNoObject4⬤⬤⬤⬤
VariablesHoldExpressions4⬤⬤⬤⬤
VariablesHoldObjects4⬤⬤⬤⬤
BaseCaseNotNeeded3⬤⬤⬤
CompareBooleanToConstant4⬤⬤⬤⬤
ConditionalIsSequence2⬤⬤
ElseAlwaysExecutes2⬤⬤
EqualityOperatorComparesListIdentities5⬤⬤⬤⬤⬤
EqualityOperatorComparesOnlyTypes4⬤⬤⬤⬤
ExpressionAssigns3⬤⬤⬤
ListLengthCannotBeZero1⬤
ListsHomogeneous2⬤⬤
MissingElseTerminates2⬤⬤
RepeatDistributes2⬤⬤
ResetStateEachLoopIteration2⬤⬤
ResetStateEachProgramExecution2⬤⬤