Review Session Biggest discrepancy questions (Top 27% scored well, bottom 27% scored poorly)

Scanning Quiz Mean 84% Median 86% Std @10%

P3 Q2 Whole Group: 52% Upper 27%*: 82% Lower 27%*: 21% Q: A string scanned by a scanner is a concatenation of all the tokens detected by the scanner. *The upper 27% and the lower 27% refer to scores on this test, I will be using this metric as it shows a divide in understanding, not just a difficult question. If you scored better than 73% of your peers you fall into the Upper 27% category, if you scored poorly you fall into the Lower 27% and will hopefully learn a lot from this review False

P3 Q1 Whole Group: 68% Upper 27%: 85% Lower 27%: 39% Q: A token produced by scanning a string can have non consecutive characters of the string. False

P3 Q7 Whole Group: 75% Upper 27%: 100% Lower 27%: 52% Q: Which is true: The character ‘a’ and ‘0’ cannot be compared in Java The character ‘a’ and ‘0’ can be compared in Java but it is not good style to make this comparison. The character ‘a’ and ‘0’ can be compared in Java and it is good style to make this comparison. B

P2 Q3 Whole Group: 35% Upper 27%: 65% Lower 27%: 21% Q: A main method must have an argument named args False

P4 Q2 Whole Group: 53% Upper 27%: 91% Lower 27%: 47% From lectures.scanning.AConsoleReadingUpperCasePrinter Make sure you input “Albert Einstein” as the input string Q: The values of variable, index, when the print is executed are: Each of the values in the range 0..scannedString.length()-1 Each of the values in the range 0..scannedString.length() 0 and 7 1 and 8 None of the above C

Class Dual Roles Quiz Mean 84% Median 86% Std @9.5%

P4 Q2 Whole Group: 66% Upper 27%: 95% Lower 27%: 33% Q: The number of properties in ALoopingFactorialSpreadsheet is the same as the number of variables in it. True

P4 Q20 Whole Group: 51% Upper 27%: 80% Lower 27%: 23% Q: The names of properties begin with lowercase letters. False

P3 Q9 Whole Group: 72% Upper 27%: 100% Lower 27%: 47% Q: "hello World" is an instance of a class. True: Extension, which class? String

P4 Q5 Whole Group: 67% Upper 27%: 95% Lower 27%: 47% Q: The number of properties in AnotherLoopingFactorialSpreadsheet is the same as the number of variables in it. False

P4 Q10 Whole Group: 79% Upper 27%: 100% Lower 27%: 52% Q: For each property of ALoopingFactorialSpreadsheet there exists a property with the same name and type in AFactorialSpreadsheetPretender. True

P4 Q26 Whole Group: 85% Upper 27%: 100% Lower 27%: 52% Q: A write method of a property named P of type T has the name setP and: takes a parameter of type T, and returns a value of type T takes a parameter of type T, and returns no value. takes no parameter, and returns a value of type T B

P4 Q27 Whole Group: 29% Upper 27%: 52% Lower 27%: 4% Q: The names and types of the properties defined by a class depend on: Only public and non public methods of the class. Only public methods of the class. Only variables of the class. Variables and public instance methods of the class. B

P2 Q21 Whole Group: 87% Upper 27%: 100% Lower 27%: 57% Q: Factorials is a stateless class. True

Constructors and Pointers Quiz Mean 83% Median 84% Std @11.25%

P3 Q10 Whole Group: 75% Upper 27%: 95% Lower 27%: 40% Q: A null pointer exception is thrown when an uninitialized Object variable is printed. False

P2 Q12 Whole Group: 72% Upper 27%: 95% Lower 27%: 45% Q: The complier: may insert a constructor in the object code always inserts a constructor in the object code. never inserts a constructor in the object code. A

P3 Q4 Whole Group: 75% Upper 27%: 95% Lower 27%: 45% Q: It is not possible to access (use) the value of an uninitialized (instance/static) global variable. False

P3 Q5 Whole Group: 82% Upper 27%: 100% Lower 27%: 50% Q: A constructor can initialize an arbitrary uninitialized local variable (declared in any method). False

P1 Q4 Whole Group: 29% Upper 27%: 54% Lower 27%: 9% Q: If c is an instance of class C (defined by us), then (by default) println(c) displays: the properties of c. the memory address of c the hashcode of c C

P2 Q5 Whole Group: 68% Upper 27%: 90% Lower 27%: 45% Q: A constructor: "constructs" the object, that is, allocates space for the instance variables of the object in memory. can initialize instance variables of an object. must initialize instance variables of an object B

Interfaces Quiz Mean 88% Median 90% Std @11.35%

P2 Q25 Whole Group: 68% Upper 27%: 100% Lower 27%: 36% Q: Interfaces: (pick all that apply) make code more reusable constrain or specify the nature of classes that implement them. provide an abstract description of the classes that implement them. none of the above. A, B, C

P2 Q14 Whole Group: 75% Upper 27%: 100% Lower 27%: 40% Q: If C1 and C2 implements I then: (choose all that apply) all instances of C1 are also instances of I. all instances of I are also instances of C1. all instances of C1 are also instances of C2. A

P1 Q10 Whole Group: 80% Upper 27%: 100% Lower 27%: 45% Q: If Java classes C1 and C2 implement the same conceptual type, and a variable c is declared to be of Java type C1,then c can be assigned an instance of C2. False

P1 Q8 Whole Group: 81% Upper 27%: 100% Lower 27%: 45% Q: If the type of variable c is class C, then the methods you can call on c depends only on the: headers of the methods declared in C. the bodies of the methods of the methods in C. the headers and bodies of the methods declared in C. A

P2 Q11 Whole Group: 4% Upper 27%: 72% Lower 27%: 22% Q: A compiler analysis of the source code of any class can always determine the class of the object assigned to any variable after a procedure call or some other statement of the program. False

P2 Q12 Whole Group: 67% Upper 27%: 100% Lower 27%: 50% Q: Given the variable declaration: I v = new C(); the operations that are allowed on v by the compiler should depend on: I C A

Mean 89.5% Median 93% Std @13.3% (*huge outlier) Graphics Quiz Mean 89.5% Median 93% Std @13.3% (*huge outlier)

Q15 Whole Group: 62% Upper 27%: 86% Lower 27%: 27% Q: The same set of properties can be used to completely represent a rectangle and image. False

Q8 Whole Group: 53% Upper 27%: 90% Lower 27%: 40% Q: In a computer coordinate system, the origin is: The lower-left corner of the screen. The upper-left corner of the screen. The lower-left corner of the window being used for a graphics operation. The upper-left corner of the window being used for a graphics operation. D

Q4 Whole Group: 84% Upper 27%: 100% Lower 27%: 59% Q: A rectangle can be completely represented by its width and height. False

Q18 Whole Group: 85% Upper 27%: 100% Lower 27%: 59% Q: A (positionable) unscalable image can be represented by an image file name and the coordinates of the upper-left corner of its bounding box. True

Q23 Whole Group: 77% Upper 27%: 100% Lower 27%: 59% Q: StructurePattern annotations can be used to create the properties of an object, that is, the getters of the properties. False

User Interface and Annotations Quiz Mean 84% Median 86% Std @11%

P2 Q13 Whole Group: 56% Upper 27%: 95% Lower 27%: 18% Q: When an object is changed from the program, ObjectEditor knows about this event and calls getters in the object to update the display of the object. False

P2 Q9 Whole Group: 75% Upper 27%: 100% Lower 27%: 36% Q: When a property is edited (in an ObjectEditor window) the setter for only that property is called. the setters for all editable properties are called. A

P1 Q4 Whole Group: 63% Upper 27%: 90% Lower 27%: 31% Q: Computation or model code is responsible for: (mark all that apply) converting user input into Java values. converting Java values into user output. determining the relationship between output and input. c

P2 Q5 Whole Group: 62% Upper 27%: 86% Lower 27%: 27% Q: In C#, to assign the value of property P of object o to variable v, we must execute a statement of the form: v = o.getP(); v = o.get(); v = o.P; None of the above C

P2 Q6 Whole Group: 67% Upper 27%: 81% Lower 27%: 27% Q: In C#, to change the value of property P of object o to expression E, we must execute code of the form: o.setP(E); o.set(E); o.P = E; None of the above. C

P3 Q3 Whole Group: 21% Upper 27%: 59% Lower 27%: 4% Q: The Java compiler processes the @EditablePropertyNames annotation of a class by: generating a setter for each property listed in the annotation. giving a warning if a property listed in the @EditablePropertyNameannotation of a class is not editable, that is, does not have a setter None of the above C

Composite Objects and Shapes Quiz Mean 76% Median 78% Std @14%

P1 Q1 Whole Group: 32% Upper 27%: 52% Lower 27%: 14% Q: The Bean properties of ALineWithObjectProperty are: (mark all that apply) Width Height Location C

P2 Q12 Whole Group: 74% Upper 27%: 100% Lower 27%: 28% Q: xAxis is a leaf variable of ACartesianPlane. False

P1 Q13 Whole Group: 65% Upper 27%: 95% Lower 27%: 33% Q: The physical structure of ALineWithObjectProperty has a parent node labeled "this“. True

P2 Q8 Whole Group: 58% Upper 27%: 90% Lower 27%: 28% Q: All structured properties of ACartesianPlane are readonly. True

P2 Q20 Whole Group: 73% Upper 27%: 100% Lower 27%: 42% Q: XAxis is a stored property of AnInefficientCartesianPlane, that is, its value is stored in an instance variable. False

P1 Q5 Whole Group: 78% Upper 27%: 95% Lower 27%: 42% Q: The debugger shows the physical structure of an object. True

P2 Q4 Whole Group: 76% Upper 27%: 100% Lower 27%: 47% Q: Calling setAxesLength in ACartesianPlane, changes the: (mark all that apply) object variable xAxis, that is, assigns a new object to this variable. primitive X property of the existing object stored in the xAxis variable. B

Composite Objects- Trees, DAGs, and Graphs Mean 81% Median 84% Std @12.6%

Q1 Whole Group: 10% Upper 27%: 26% Lower 27%: 5% Q: Annotations can be used to ask ObjectEditor to ignore certain nodes in the logical structure of an object. False

Q15 Whole Group: 68% Upper 27%: 100% Lower 27%: 31% Q: If we create a cycle in a widget structure, Java: removes the cycle. ignores the operation that creates a cycle. gives a compile-time error. gives a runtime error. D

Q5 Whole Group: 75% Upper 27%: 100% Lower 27%: 42% Q: In WindowTree Creator, a JPanel instance is: the root of the widget tree. an interior node of the widget tree. a leaf of the widget tree. B

Q6 Whole Group: 75% Upper 27%: 100% Lower 27%: 42% Q: In WindowTree Creator, a JTextField instance is: the root of the widget tree. an interior node of the widget tree. a leaf of the widget tree. C

Q4 Whole Group: 60% Upper 27%: 78% Lower 27%: 26% Q: Which nodes of the logical structure of a frame can be displayed? (mark all that apply) root (the frame). interior nodes. leaf nodes. A,B,C

Composite Objects- Trees, DAGs, and Graphs Mean 76.3% Median 75.9% Std @12.4%

P2 Q9 Whole Group: 50% Upper 27%: 89% Lower 27%: 15% Q: if indexOf(element) cannot find element, it returns: -1 the number of filled elements (size) in the underlying array. the size of the underlying array. c

P5 Q5 Whole Group: 48% Upper 27%: 94% Lower 27%: 21% Q: The physical structure of an object cannot have two variables with the same name. F

P6 Q7 Whole Group: 69% Upper 27%: 94% Lower 27%: 21% Q: A superclass constructor can be called from any method of a subclass. False

P1 Q9 Whole Group: 51% Upper 27%: 84% Lower 27%: 15% Q: We can define our own collection type that uses array syntax to manipulate the elements of the collection. False

P2 Q7 Whole Group: 41% Upper 27%: 84% Lower 27%: 15% Q: The index() method of AnInheritingStringDatabase calls an instance method in its superclass without specifying the target of the call. True

P4 Q4 Whole Group: 61% Upper 27%: 94% Lower 27%: 26% Q: System.out.println(o) calls: the toString() method on o. the println() method on o. getter() methods of o. A

P6 Q8 Whole Group: 65% Upper 27%: 89% Lower 27%: 21% Q: If no super() call is made in a constructor: an exception is thrown. no superclass constructor is called. a call to the parameterless super constructor is automatically added as the first statement in the constructor. C

P6 Q4 Whole Group: 65% Upper 27%: 89% Lower 27%: 26% Q: If C is a subclass of E, and an object c of type C is instantiated, then: a constructor of only C is called. a constructor of only E is called. a constructor of C and E are called. C