Tag: programming languages

Questions Related to programming languages

Correct way of method declaration within interface :
technology programming languages

  1. void run();

  2. protected void go();

  3. static void get();

  4. public abstract set();

  5. none of these

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Correct Option: A

Which one is true :
technology programming languages

  1. interface declares constant and instance variables.

  2. The abstract modifier can be combined with the static modifier .

  3. native modifier can be applied only on method.

  4. synchronized modifier can be applied to method as well as class.

  5. none of these

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Correct Option: C

Which program will give correct output :
technology programming languages

  1. class cons{ cons() { } public void cons(); public static void main (String[] aa){ cons b=new cons(); } }

  2. public class cons { cons() { } public cons(int x,int y) { System.out.print(x +" "+ y); } public static void main (String[] aa){ cons b=new cons(); cons obj=new cons(4,2); } }

  3. public class cons { public cons(int x) { System.out.print(x); } public static void main (String[] aa){ cons b=new cons(); } }

  4. class cons{ cons() { } public float foo () { double f = 32; return f; } public static void main (String[] aa){ cons b=new cons(); } }

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Correct Option: B

What is the output of the following code when compiled and run? Select two correct answers. public class TechnoSample { public static void main(String[] args){ for(int i = 0; i <> System.out.println(getPrimitive(127)); //line 1 } } public static int getPrimitive(byte b) { //line 2 return (short)(Math.random()*b); //line 3 } }
technology programming languages

  1. Compilation error on line 1

  2. Compilation error on line 2

  3. Compilation error on line 3

  4. Line 3 compiles fine

  5. Prints 10 random numbers between 0 and 127

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Correct Option: A,D

Select three correct statements.
technology programming languages

  1. A static method may override another static method

  2. A static method cannot override a non-static method

  3. A non-static method cannot override a static method

  4. A non-static method may be overloaded by a static method

  5. A synchronized method cannot be overridden

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Correct Option: B,C,D

Select three correct statements about the following code :-- public class TechnoSample { public static void main(String[] args) { TechnoSample myref = new TechnoSampleSub(); try{ myref.test(); } catch(Exception e){} } void test() throws Exception{ System.out.println("In TechnoSample"); throw new Exception(); } } class TechnoSample Sub extends TechnoSample { void test() { System.out.println("In TechnoSampleSub"); } }
technology programming languages

  1. The try-catch block that encloses myref.test(); is mandatory for the code to compile

  2. Prints: In TechnoSample

  3. Prints: In TechnoSampleSub

  4. Method test() in class TechnoSampleSub has no obligation to declare a throws clause

  5. An exception is thrown at runtime

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Correct Option: A,C,D

What will be output for the following program? public class Boxing2 { public static void main(String[] args) { byte b = 10; method(b); } static void method(int i){ System.out.println("Primitivae Type call"); } static void method(Integer i){ System.out.println("Wrapper Type Call"); } }
technology programming languages

  1. Wrapper Type Call

  2. Primitive Type Call

  3. Compiler Error

  4. Compiles fine, throws runtime exception

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Correct Option: B

What will be the output of the following program? package wrapper_boxing; public class WrapperTest2 { public static void main(String[] args) { Boolean bool1 = new Boolean(true); Boolean bool2 = new Boolean(false); Boolean bool3 = new Boolean("false"); Boolean bool4 = new Boolean(bool1); System.out.println(bool1.equals(bool4)); System.out.println(bool2 == bool3); System.out.println(bool1 == bool4); } }
technology programming languages

  1. The program will not compile because the creation of bool4 object will cause compilation error.

  2. The program will produce the output 'true false false'.

  3. The program will produce the output 'true true true'.

  4. The program will output 'true false true'.

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Correct Option: B

What will be the output of the following program? public class Ques09 { public static void main(String[] args) { Integer a = null; a = new Integer(10); int b = 20; a = b; a = 30; System.out.println(a++); short s = 100; a = s; System.out.println(a--); } }
technology programming languages

  1. The program won't compile.

  2. The program will throw a run-time exception.

  3. The program will output '31 100'

  4. The program will output '31 99'

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Correct Option: A

What will be the output of the following program? import java.io.ByteArrayInputStream; import java.io.InputStream; public class Ques04 { public static void main(String[] args) throws Exception{ byte buffer[] = {'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'}; InputStream inputStream = new ByteArrayInputStream(buffer); inputStream.read();inputStream.read(); inputStream.skip(4); System.out.println((char)inputStream.read()); } }
technology programming languages

  1. The program will raise a run-time exception telling that it is not possible to skip bytes in the middle of a reading operation.

  2. The program will output 'd'.

  3. The program will output 'e'.

  4. The program will output 'g'.

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Correct Option: D