Tag: programming languages

Questions Related to programming languages

Is this code legal ? class ExceptionA extends Exception {} class ExceptionB extends ExceptionA {} class A{ void thrower() throws ExceptionA{ throw new ExceptionA(); } } public class B extends A{ void thrower() throws ExceptionB{ throw new ExceptionB(); } }
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  1. yes

  2. no

  3. DO NOT SELECT 1

  4. DO NOT SELECT 2

Show answer
Correct Option: A

What will be output for the following program? public class BoxingTest { public static void main(String[] args) { byte b = 10; method(b); } static void method(int i){ System.out.println("Primitive Type call"); } static void method(Integer i){ System.out.println("Wrapper Type Call"); } }
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  1. Wrapper Type Call

  2. Primitive Type Call

  3. Compiler Error

  4. Compiles fine, throws runtime exception

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Correct Option: B

How does the set collection deal with duplicate elements?
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  1. An exception is thrown if you attempt to add an element with a duplicate value.

  2. The add method returns false if you attempt to add an element with a duplicate value.

  3. A set may contain elements that return duplicate values from a call to the equals method.

  4. Duplicate values will cause an error at compile time.

Show answer
Correct Option: B

What will be the outcome of line no. 9 in the following program ? 1. public class SearchArray { 2. public static void main(String[] args) { 3. String[] strArr = {"one","two","three","four","five","six","seven"}; 4. boolean[] boolArr = {true,false,false,true,false}; 5. int[] intArr = {22,11,66,99}; 6. Arrays.sort(intArr); 7. for(int n=0; n
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  1. -3

  2. 3

  3. -4

  4. 4

Show answer
Correct Option: C

What will happen when you attempt to compile and run the following code? public class Bground extends Thread{ public static void main(String argv[]){ Bground b = new Bground(); b.run(); } public void start(){ for (int i = 0; i <10; i++){ System.out.println("Value of i = " + i); } } }

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  1. A compile time error indicating that no run method is defined for the Thread class.

  2. A run time error indicating that no run method is defined for the Thread class.

  3. Clean compile and at run time the values 0 to 9 are printed out.

  4. Clean compile but no output at runtime.

Show answer
Correct Option: D

AI Explanation

To answer this question, let's go through each option:

Option A) A compile time error indicating that no run method is defined for the Thread class. This option is incorrect. The code defines a run method in the Bground class, which extends the Thread class. Therefore, there is a run method defined for the Thread class.

Option B) A run time error indicating that no run method is defined for the Thread class. This option is also incorrect. As mentioned earlier, the code defines a run method in the Bground class, which extends the Thread class. Therefore, there is a run method defined for the Thread class.

Option C) Clean compile and at run time the values 0 to 9 are printed out. This option is incorrect. Although the code defines a start method in the Bground class, it doesn't actually start a new thread by calling the start method. Instead, it directly calls the run method on the Bground object. This means that the code will execute the for loop and print the values 0 to 9, but it will do so in the main thread, not in a separate thread.

Option D) Clean compile but no output at runtime. This option is correct. The code will compile without any errors, but it will not produce any output at runtime. This is because the start method, which would have started a new thread and executed the code in the run method concurrently, is not called. Instead, the code directly calls the run method, which executes the for loop in the main thread. Since the code doesn't use the start method, there is no separate thread to execute the for loop and print the values.

Therefore, the correct answer is option D) Clean compile but no output at runtime.

What will be the output of the following program? package scjp.threadTest; public class Ques01 { public static void main(String[] args) { HelloThread hello = new HelloThread(); hello.start(); } } class MyThread implements Runnable{ @Override public void run() { System.out.println("My thread"); } } class HelloThread extends Thread{ public void start(){ System.out.println("Hello thread"); } public void run(){ Thread thread = new Thread(new MyThread()); thread.start(); } }
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  1. The program will output 'Hello Thread' and 'My Thread'.

  2. The program will output 'Hello Thread'.

  3. The program will output 'My Thread' and 'Hello Thread'.

  4. The order of the outputs is not will vary upon execution.

Show answer
Correct Option: B

Program output : package com.collection.examples; import java.util.HashSet; public class HashSetExample { public static void main(String[] args) { HashSet s = new HashSet();//1 for(short i = 0; i<100;i++){ //2 s.add(i); //3 s.remove(i-1); //4 } System.out.println(s.size()); //5 } }
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  1. NumberFormat Exception

  2. 100

  3. Compilation fails at line 4

  4. 99

Show answer
Correct Option: B

Which of the following options is true for the following program: try { if (choice) { while (true) } else { system .exit(1): } }finally { codetocleanup(); }
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  1. Runtime Exception

  2. finally block will be executed

  3. finally block will not be executed

  4. Compilation error in else block

Show answer
Correct Option: C

Is this code legal ? class ExceptionA extends Exception {} class ExceptionB extends ExceptionA {} public class Test{ void thrower() throws ExceptionB{ throw new ExceptionB(); } public static void main(String[] args){ Test t = new Test(); try{t.thrower();} catch(ExceptionA e) {} catch(ExceptionB e) {} } }
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  1. yes

  2. no

  3. DO NOT SELECT 1

  4. DO NOT SELECT 2

Show answer
Correct Option: B

Is this code legal ? class ExceptionA extends Exception {} class ExceptionB extends ExceptionA {} class A{ void thrower() throws ExceptionA{ throw new ExceptionA(); } } public class B extends A{ void thrower() throws ExceptionB{ throw new ExceptionB(); } }
technology programming languages

  1. yes

  2. no

  3. DO NOT SELECT 1

  4. DO NOT SELECT 2

Show answer
Correct Option: A