SCJP考试题310-025(第二套)91-147/147

<script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"> </script> 快放寒假咯,向JAVA中文技术网的工作人员问好,向所有访问该页面的朋友问好,祝你们天天快乐,心想事成!本人快要回家和家人团聚了,呵呵!将最后的几题贴出来! 310-025 Leading the way in IT testing and certification tools,QUESTION NO: 92 Given: 1. String foo = “blue”; 2. Boolean[]bar = new Boolean [1]; 3. if (bar[0]) { 4. foo = “green”; 5. } What is the result? A. Foo has the value of “” B. Foo has the value of null. C. Foo has the value of “blue” D. Foo has the value of “green” E. An exception is thrown. F. The code will not compile. Answer: F QUESTION NO: 93 Exhibit: 1. public class X { 2. public static void main (String[]args) { 3. String s1 = new String (“true”); 4. Boolean b1 = new Boolean (true); 5. if (s2.equals(b1)) { 6. System.out.printIn(“Equal”); 7. } 8. } 9. } What is the result? A. The program runs and prints nothing. B. The program runs and prints “Equal” C. An error at line 5 causes compilation to fail. D. The program runs but aborts with an exception. Answer: A QUESTION NO: 94 Given: 1. public class Foo { 2. public static void main (String []args) { 3. int i = 1; 4. int j = i ; 5. if ((i> j) && (i ==j)) { 6. i =j; 7. } 8. } 9. } What is the final value of i? A. 1 B. 2 C. 3 D. 4 E. 5 Answer: B QUESTION NO: 95 Exhibit: 1. public class X { 2. public static void main (String[]args) { 3. string s = new string (“Hello”); 4. modify(s); 5. System.out.printIn(s); 6. } 7. 8. public static void modify (String s) { 9. s = “world!”; 10. } 11. } What is the result? E. The program runs and prints “Hello” F. An error causes compilation to fail. G. The program runs and prints “Hello world!” H. The program runs but aborts with an exception. Answer: A QUESTION NO: 96 Which two are equivalent? (Choose Two) A. 16>4 B. 16/2 C. 16*4 D. 16>>2 E. 16/2^2 F. 16>>>2 Answer: D, E QUESTION NO: 97 Exhibit: 1. public class X { 2. public static void main (String[]args) { 3. int [] a = new int [1] 4. modify(a); 5. System.out.printIn(a[0]); 6. } 7. 8. public static void modify (int[] a) { 9. a[0] ; 10. } 11. } What is the result? A. The program runs and prints “0” B. The program runs and prints “1” C. The program runs but aborts with an exception. D. An error “possible undefined variable” at line 4 causes compilation to fail. E. An error “possible undefined variable” at line 9 causes compilation to fail. Answer: B QUESTION NO: 98 Given: 13. public class Foo { 14. public static void main (String [] args) { 15. StringBuffer a = new StringBuffer (“A”); 16. StringBuffer b = new StringBuffer (“B”); 17. operate (a,b); 18. system.out.printIn{a “,” b}; 19. ) 20. static void operate (StringBuffer x, StringBuffer y) { 21. y.append {x}; 22. y = x; 23. ) 24. } What is the result? A. The code compiles and prints “A,B”. B. The code compiles and prints “A, BA”. C. The code compiles and prints “AB, B”. D. The code compiles and prints “AB, AB”. E. The code compiles and prints “BA, BA”. F. The code does not compile because “ ” cannot be overloaded for stringBuffer. Answer: B QUESTION NO: 99 Given: 1. public class X { 2. public static void main (String[] args) { 3. byte b = 127; 4. byte c = 126; 5. byte d = b c; 6. } 7. } Which statement is true? A. Compilation succeeds and d takes the value 253. B. Line 5 contains an error that prevents compilation. C. Line 5 throws an exception indicating “Out of range” D. Line 3 and 4 contain error that prevent compilation. E. The compilation succeeds and d takes the value of 1. Answer: B QUESTION NO: 100 Given: 1. public class WhileFoo { 2. public static void main (String []args) { 3. int x= 1, y = 6; 4. while (y--) {x--;} 5. system.out.printIn(“x=” x “y =” y); 6. } 7. } What is the result? A. The output is x = 6 y = 0 B. The output is x = 7 y = 0 C. The output is x = 6 y = -1 D. The output is x = 7 y = -1 E. Compilation will fail. Answer: E QUESTION NO: 101 Which statement is true? A. The Error class is a untimeException. B. No exceptions are subclasses of Error. C. Any statement that may throw an Error must be enclosed in a try block. D. Any statement that may throw an Exception must be enclosed in a try block. E. Any statement that may thro a runtimeException must be enclosed in a try block. Answer: D QUESTION NO: 102 Exhibit: 1. int I=1, j=0 2. 3. switch(i) { 4. case 2: 5. j =6; 6. 7. case 4: 8. j =1; 9. 10. default: 11. j =2; 12. 13. case 0: 14. j =4; 15. } 16. What is the value of j at line 16? A. 0 B. 1 C. 2 D. 4 E. 6 Answer: AE QUESTION NO: 103 Given: 1. switch (i) { 2. default: 3. System.out.printIn(“Hello”); 4. ) What is the acceptable type for the variable i? A. Byte B. Long C. Float D. Double E. Object F. A and B G. C and D Answer: A QUESTION NO: 104 You need to store elements in a collection that guarantees that no duplicates are stored. Which two interfaces provide that capability? (Choose Two) A. Java.util.Map B. Java.util.Set C. Java.util.List D. Java.util.StoredSet E. Java.util.StoredMap F. Java.util.Collection Answer: B, D QUESTION NO: 105 Which statement is true for the class java.util.ArrayList? A. The elements in the collection are ordered. B. The collection is guaranteed to be immutable. C. The elements in the collection are guaranteed to be unique. D. The elements in the collection are accessed using a unique key. E. The elements in the collections are guaranteed to be synchronized. Answer: A QUESTION NO: 106 Exhibit: 1. public class X implements Runnable( 2. private int x; 3. private int y; 4. 5. public static void main(String[]args) 6. X that = new X(); 7. (new Thread(that)).start(); 8. (new Thread(that)).start(); 9. ) 10. 11. public void run() ( 12. for (;;) ( 13. x ; 14. y ; 15. System.out.printIn(“x=” x “, y = ” y); 16. ) 17. ) 18. ) What is the result? A. Errors at lines 7 and 8 cause compilation to fail. B. The program prints pairs of values for x and y that might not always be the same on the same line (for example, “x=2, y=1”). C. The program prints pairs of values for x and y that are always the same on the same line (for example, “x=1, y=1”. In addition, each value appears twice (for example, “x=1, y=1” followed by “x=1, y=1”). D. The program prints pairs of values for x and y that are always the same on the same line (for example, “x=1, y=1”. In addition, each value appears only for once (for example, “x=1, y=1” followed by “x=2, y=2”). Answer: D QUESTION NO: 107 Given: 1. public class SyncTest { 2. private int x; 3. private int y; 4. public synchronized void setX (int i) (x=1;) 5. public synchronized void setY (int i) (y=1;) 6. public synchronized void setXY(int 1)(set X(i); setY(i);) 7. public synchronized Boolean check() (return x !=y;) 8. ) Under which conditions will check () return true when called from a different class? A. Check() can never return true. B. Check() can return true when setXY is called by multiple threads. C. Check() can return true when multiple threads call setX and setY separately. D. Check() can only return true if SyncTest is changed to allow x and y to be set separately. Answer: A QUESTION NO: 108 Which is a method of the MouseMotionListener interface? A. Public void mouseDragged(MouseEvent) B. Public boolean mouseDragged(MouseEvent) C. Public void mouseDragged(MouseMotionEvent) D. Public boolean MouseDragged(MouseMotionEvent) E. Public boolean mouseDragged(MouseMotionEvent) Answer: A QUESTION NO: 109 Given: 1. String foo = “base”; 2. foo.substring(0,3); 3. foo.concat(“ket”); 4. foo = “ball”; 5. Type the value of foo at line 8. Answer: BASEBALL QUESTION NO 110 Given: 1. public class Test { 2. public static void leftshift(int i, int j) { 3. i<<=j; 4. } 5. public static void main(String args[]) { 6. int i = 4, j = 2; 7. leftshift(i, j); 8. System.out.printIn(i); 9. } 10. } What is the result? A. 2 B. 4 C. 8 D. 16 E. The code will not compile. Answer: B QUESTION NO 111 Given: 1. public class Foo { 2. private int val; 3. public foo(int v) (val = v;) } 4. public static void main (String [] args) { 5. Foo a = new Foo (10); 6. Foo b = new Foo (10); 7. Foo c = a; 8. int d = 10; 9. double e = 10.0; 10. } 11. } Which three logical expression evaluate to true? (Choose Three) A. (a ==c) B. (d ==e) C. (b ==d) D. (a ==b) E. (b ==c) F. (d ==10.0) Answer: A, B, F QUESTION NO 112 Exhibit: 1. public class X { 2. private static int a; 3. 5. public static void main (String[] args) { 6. modify (a); 7. } 8. 9. public static void modify (int a) { 10. a ; 11. } 12. } What is the result? A. The program runs and prints “0” B. The program runs and prints “1” C. The program runs but aborts with an exception. D. En error “possible undefined variable” at line 5 causes compilation to fail. F. En error “possible undefined variable” at line 10 causes compilation to fail. Answer: A QUESTION NO 113 Exhibit: 1. public class Test { 2. public static void replaceJ(string text) { 3. text.replace (‘j’, ‘l’); 4. } 5. 6. public static void main(String args[]) { 7. string text = new String (“java”) 8. replaceJ(text); 9. system.out.printIn(text); 10. } 11. } What is the result? A. The program prints “lava” B. The program prints “java” C. An error at line 7 causes compilation to fail. D. Compilation succeeds but the program throws an exception. Answer: B QUESTION NO 114 Which two are equivalent? (Choose Two) A. 3/2 B. 3<2 C. 3*4 D. 3<<2 E. 3*2^2 F. 3<<<2 Answer: C, D QUESTION NO 115 What is the numerical range of a char? A. 0 . . . 32767 B. 0 . . . 65535 C. –256 . . . 255 D. –32768 . . . 32767 E. Range is platform dependent. Answer: B QUESTION NO 116 Given: 1. public class Test { 2. public static void main (String []args) { 3. unsigned byte b = 0; 4. b--; 5. 6. } 7. } What is the value of b at line 5? A. -1 B. 255 C. 127 D. Compilation will fail. E. Compilation will succeed but the program will throw an exception at line 4. Answer: D QUESTION NO 117 Given: 1. public class Foo { 2. public void main (String [] args) { 3. system.out.printIn(“Hello World.”); 4. } 5. } What is the result? A. An exception is thrown. B. The code does no compile. C. “Hello World.” Is printed to the terminal. D. The program exits without printing anything. Answer: A QUESTION NO 118 Given: 1. //point X 2. public class foo ( 3. public static void main (String[]args) throws Exception { 4. java.io.printWriter out = new java.io.PrintWriter ( 5. new java.io.outputStreamWriter (System.out), true; 6. out.printIn(“Hello”); 7. } 8. } Which statement at PointX on line 1 allows this code to compile and run? A. Import java.io.*; B. Include java.io.*; C. Import java.io.PrintWriter; D. Include java.io.PrintWriter; E. No statement is needed. Answer: E QUESTION NO 119 Which will declare a method that is available to all members of the same package and can be referenced without an instance of the class? A. Abstract public void methoda(); B. Public abstract double methoda(); C. Static void methoda(double d1){} D. Public native double methoda() {} E. Protected void methoda(double d1) {} Answer: C QUESTION NO 120 Which type of event indicates a key pressed on a java.awt.Component? A. KeyEvent B. KeyDownEvent C. KeyPressEvent D. KeyTypedEvent E. KeyPressedEvent Answer: A QUESTION NO 121 Exhibit: 1. import java.awt.*; 2. 3. public class X extends Frame { 4. public static void main (String [] args) { 5. X x = new X(); 6. x.pack(); 7. x.setVisible(true); 8. } 9. 10. public X() { 11. setLayout (new BordrLayout()); 12. Panel p = new Panel (); 13. add(p, BorderLayout.NORTH); 14. Button b = new Button (“North”); 15. p.add(b): 16. Button b = new Button (“South”); 17. add(b1, BorderLayout.SOUTH): 18. } 19. } Which two statements are true? (Choose Two) A. The buttons labeled “North” and “South” will have the same width. B. The buttons labeled “North” and “South” will have the same height. C. The height of the button labeled “North” can very if the Frame is resized. D. The height of the button labeled “South” can very if the Frame is resized. E. The width of the button labeled “North” is constant even if the Frame is resized. F. The width of the button labeled “South” is constant even if the Frame is resized. Answer: B, E QUESTION NO 122 How can you create a listener class that receives events when the mouse is moved? A. By extending MouseListener. B. By implementing MouseListener. C. By extending MouseMotionListener. D. By implementing MouseMotionListener. E. Either by extending MouseMotionListener or extending MouseListener. F. Either by implementing MouseMotion Listener or implementing MouseListener. Answer: D QUESTION NO 123 Which statement is true? A. A grid bag layout can position components such that they span multiple rows and/or columns. B. The “North” region of a border layout is the proper place to locate a menuBar component in a Frame. C. Components in a grid bag layout may either resize with their cell, or remain centered in that cell at their preferred size. D. A border layout can be used to position a component that should maintain a constant size even when the container is resized. Answer: A QUESTION NO 124 You want a class to have access to members of another class in the same package. Which is the most restrictive access modifier that will accomplish that will accomplish this objective? A. Public B. Private C. Protected D. Transient E. No access modifier is required. Answer: E QUESTION NO 125 Which two statements are true regarding the creation of a default constructor? (Choose Two) A. The default constructor initializes method variables. B. The default constructor invokes the no-parameter constructor of the superclass. C. The default constructor initializes the instance variables declared in the class. D. If a class lacks a no-parameter constructor,, but has other constructors, the compiler creates a default constructor. E. The compiler creates a default constructor only when there are no other constructors for the class. Answer: C, E QUESTION NO 126 Given: 1. public class OuterClass { 2. private double d1 1.0; 3. //insert code here 4. } You need to insert an inner class declaration at line2. Which two inner class declarations are valid? (Choose Two) A. static class InnerOne { public double methoda() {return d1;} } B. static class InnerOne { static double methoda() {return d1;} } C. private class InnerOne { public double methoda() {return d1;} } D. protected class InnerOne { static double methoda() {return d1;} } E. public abstract class InnerOne { public abstract double methoda(); } Answer: C, E QUESTION NO 127 Which two declarations prevent the overriding of a method? (Choose Two) A. Final void methoda() {} B. Void final methoda() {} C. Static void methoda() {} D. Static final void methoda() {} E. Final abstract void methoda() {} Answer: A, D QUESTION NO 128 Given: 1. public class Test { 2. public static void main (String args[]) { 3. class Foo { 4. public int i = 3; 5. } 6. Object o = (Object) new Foo(); 7. Foo foo = (Foo)o; 8. System.out.printIn(foo. i); 9. } 10. } What is the result? A. Compilation will fail. B. Compilation will succeed and the program will print “3” C. Compilation will succeed but the program will throw a ClassCastException at line 6. D. Compilation will succeed but the program will throw a ClassCastException at line 7. Answer: B QUESTION NO 129 Which two create an instance of an array? (Choose Two) A. int[] ia = new int [15]; B. float fa = new float [20]; C. char[] ca = “Some String”; D. Object oa = new float[20]; E. Int ia [][] = (4, 5, 6) (1, 2, 3) Answer: A, D QUESTION NO 130 Given: 1. public class ExceptionTest { 2. class TestException extends Exception {} 3. public void runTest () throws TestException {} 4. public void test () /* Point X*/ { 5. runTest (); 6. } 7. } At point X on line 4, which code can be added to make the code compile? A. Throws Exception. B. Catch (Exception e). C. Throws RuntimeException. D. Catch (TestException e). E. No code is necessary. Answer: B QUESTION NO 131 Exhibit: 1. public class SwitchTest { 2. public static void main (String []args) { 3. System.out.PrintIn(“value =” switchIt(4)); 4. } 5. public static int switchIt(int x) { 6. int j = 1; 7. switch (x) { 8. case 1: j ; 9. case 2: j ; 10. case 3: j ; 11. case 4: j ; 12. case 5: j ; 13. default:j ; 14. } 15. return j x; 16. } 17. } What is the output from line 3? A. Value = 3 B. Value = 4 C. Value = 5 D. Value = 6 E. Value = 7 F. Value = 8 Answer: F QUESTION NO 132 Which four types of objects can be thrown using the throw statement? (Choose Four) A. Error B. Event C. Object D. Exception E. Throwable F. RuntimeException Answer: A, D, E, F QUESTION NO 133 Given: 1. public class ForBar { 2. public static void main(String []args) { 3. int i = 0, j = 5; 4. tp: for (;;) { 5. i ; 6. for(;;) 7. if(i > --j) break tp; 8. } 9. system.out.printIn(“i = ” i “, j = “ j); 10. } 11. } What is the result? A. The program runs and prints “i=1, j=0” B. The program runs and prints “i=1, j=4” C. The program runs and prints “i=3, j=4” D. The program runs and prints “i=3, j=0” E. An error at line 4 causes compilation to fail. F. An error at line 7 causes compilation to fail. Answer: A QUESTION NO 134 Which two can directly cause a thread to stop executing? (Choose Two) A. Exiting from a synchronized block. B. Calling the wait method on an object. C. Calling the notify method on an object. D. Calling the notifyAll method on an object. E. Calling the setPriority method on a thread object. Answer: B, E QUESTION NO 135 Given: 1. public class Foo implements Runnable ( 2. public void run (Thread t) { 3. system.out.printIn(“Running.”); 4. } 5. public static void main (String[] args) { 6. new thread (new Foo()).start(); 7. ) 8. ) What is the result? A. An exception is thrown. B. The program exists without printing anything. C. An error at line 1 causes compilation to fail. D. An error at line 6 causes the compilation to fail. E. “Running” is printed and the program exits. Answer: C QUESTION NO 136 Which constructs a DataOutputStream? A. New dataInputStream(“in.txt”); B. New dataInputStream(new file(“in.txt”)); C. New dataInputStream(new writer(“in.txt”)); D. New dataInputStream(new FileWriter(“in.txt”)); E. New dataInputStream(new InputStream(“in.txt”)); F. New dataInputStream(new FileInputStream(“in.txt”)); Answer: F QUESTION NO 137 Which can be used to decode charS for output? A. Java.io.InputStream. B. Java.io.EncodedReader. C. Java.io.InputStreamReader. D. Java.io.InputStreamWriter. E. Java.io.BufferedInputStream. Answer: C QUESTION NO 138 Given: 1. public class Test { 2. public static void main (String [] args) { 3. string foo = “blue”; 4. string bar = foo; 5. foo = “green”; 6. System.out.printIn(bar); 7. } 8. } What is the result? A. An exception is thrown. B. The code will not compile. C. The program prints “null” D. The program prints “blue” E. The program prints “green” Answer: D QUESTION NO 139 Which code determines the int value foo closest to a double value bar? A. Int foo = (int) Math.max(bar); B. Int foo = (int) Math.min(bar); C. Int foo = (int) Math.abs(bar); D. Int foo = (int) Math.ceil(bar); E. Int foo = (int) Math.floor(bar); F. Int foo = (int) Math.round(bar); Answer: F QUESTION NO 140 Which two demonstrate encapsulation of data? (Choose Two) A. Member data have no access modifiers. B. Member data can be modified directly. C. The access modifier for methods is protected. D. The access modifier to member data is private. E. Methods provide for access and modification of data. Answer: D, E QUESTION NO 141 Exhibit: 1. class A { 2. public String toString () { 3. return “4”; 4. } 5. } 6. class B extends A { 7. 8. public String toString () { 8. return super.toString() “3”; 9. } 10. } 11. public class Test { 12. public static void main(String[]args) { 13. System.out.printIn(new B()); 14. } 15. } What is the result? A. Compilation succeeds and 4 is printed. B. Compilation succeeds and 43 is printed. C. An error on line 9 causes compilation to fail. D. An error on line 14 causes compilation to fail. E. Compilation succeeds but an exception is thrown at line 9. Answer: B QUESTION NO 142 Which two statements are true? (Choose Two) A. An anonymous inner class can be declared inside of a method B. An anonymous inner class constructor can take arguments in some situation. C. An anonymous inner class that is a direct subclass that is a direct subclass of Object can implement multiple interfaces. D. Even if a class Super does not implement any interfaces, it is still possible to define an anonymous inner class that is an immediate subclass of Super that implements a single interface. E. Event if a class Super does not implement any interfaces, it is still possible to define an anonymous inner class that is an immediate subclass of Super that implements multiple interfaces. Answer: A, B QUESTION NO 143 Given: 1. public class MethodOver { 2. private int x, y; 3. private float z; 4. public void setVar(int a, int b, float c){ 5. x = a; 6. y = b; 7. z = c; 8. } 9. } Which two overload the setVar method? (Choose Two) A. void setVar (int a, int b, float c){ x = a; y = b; z = c; } B. public void setVar(int a, float c, int b) { setVar(a, b, c); } C. public void setVar(int a, float c, int b) { this(a, b, c); } D. public void setVar(int a, float b){ x = a; z = b; } E. public void setVar(int ax, int by, float cz) { x = ax; y = by; z = cz; } Answer: B, D QUESTION NO 144 Which statements about static inner classes are true? (Choose Two) A. A static inner class requires a static initializer. B. A static inner class requires an instance of the enclosing class. C. A static inner class has no reference to an instance of the enclosing class. D. A static inner class has access to the non-static members of the outer class. E. Static members of a static inner class can be referenced using the class name of the static inner class. Answer: C, E QUESTION NO 145 Given: 1. public class X { 2. public object m () { 3. object o = new float (3.14F); 4. object [] oa = new object [1]; 5. oa[0]= o; 6. o = null; 7. oa[0] = null; 9. return o; 9. } 10. } When is the float object created in line 3, eligible for garbage collection? A. Just after line 5. B. Just after line 6. C. Just after line 7. D. Just after line 8(that is, as the method returns). Answer: C QUESTION NO 146 Which two interfaces provide the capability to store objects using a key-value pair? (Choose Two) A. Java.util.Map. B. Java.util.Set. C. Java.util.List. D. Java.util.StoredSet. E. Java.util.StoredMap. F. Java.util.Collection. Answer: A, E QUESTION NO 147 Which interface does java.util.Hashable implement? A. Java.util.Map. B. Java.util.List. C. Java.util.Hashable. D. Java.util.Collection. Answer: A