certcrunch.com Questions of the Day (IT Certification Test)

Q1. Given: 1 class Ping extends Utils { 2 public static void main(String [] args) { 3 Utils u = new Ping(); 4 System.out.print(u.getInt(args[0])); 5 } 6 int getInt(String arg) { 7 return Integer.parseInt(arg); 8 } 9 } 10 class Utils { 11 int getInt(String x) throws Exception { return 7; } 12 } And the following three possible changes: C1. Declare that main() throws an Exception. C2. Declare that Ping.getInt() throws an Exception. C3. Wrap the invocation of getInt() in a try / catch block. Which change(s) allow the code to compile? (Choose all that apply.)

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A. Just C1 is sufficient. B. Just C2 is sufficient. C. Just C3 is sufficient. D. Both C1 and C2 are required. E. Both C1 and C3 are required. F. Both C2 and C3 are required. G. All three changes are required.

Q2. Given two files: package pkg; public class Kit { public String glueIt(String a, String b) { return a+b; } } import pkg.*; class UseKit { public static void main(String[] args) { String s = new Kit().glueIt(args[1], args[2]); System.out.println(s); } } And the following sub-directory structure: test |--UseKit.class | com |--KitJar.jar If the current directory is test, and the file pkg/Kit.class is in KitJar.jar, which command line will produce the output bc ? (Choose all that apply.)

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A. java UseKit b c B. java UseKit a b c C. java -classpath com UseKit b c D. java -classpath com:. UseKit b c E. java -classpath com/KitJar.jar UseKit b c F. java -classpath com/KitJar.jar UseKit a b c G. java -classpath com/KitJar.jar:. UseKit b c H. java -classpath com/KitJar.jar:. UseKit a b c

Q3. Given: 1 class Example { 2 public static void main(String[] args) { 3 Short s = 15; 4 Boolean b; 5 // insert code here 6 } 7 } Which, inserted independently at line 5, will compile? (Choose all that apply.)

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A. b = (Number instanceof s); B. b = (s instanceof Short); C. b = s.instanceof(Short); D. b = (s instanceof Number); E. b = s.instanceof(Object); F. b = (s instanceof String);

Q4. Given: class Knowing { static final long tooth = 343L; static long doIt(long tooth) { System.out.print(++tooth + " "); return ++tooth; } public static void main(String[] args) { System.out.print(tooth + " "); final long tooth = 340L; new Knowing().doIt(tooth); System.out.println(tooth); } } What is the result?

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A. 343 340 340 B. 343 340 342 C. 343 341 342 D. 343 341 340 E. 343 341 343 F. Compilation fails. G. An exception is thrown at runtime.

Q5. The following block of code creates a Thread using a Runnable target: Runnable target = new MyRunnable(); Thread myThread = new Thread(target); Which of the following classes can be used to create the target, so that the preceding code compiles correctly?

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A. public class MyRunnable extends Runnable{public void run(){}} B. public class MyRunnable extends Object{public void run(){}} C. public class MyRunnable implements Runnable{public void run(){}} D. public class MyRunnable implements Runnable{void run(){}} E. public class MyRunnable implements Runnable{public void start(){}}