Tag: technology

Questions Related to technology

class Sub extends Super{ String name; Sub(String s) { super(s); name=s; } public static void main(String args[]){ Super sup = new Super("First"); Sub sub = new Sub("Second"); System.out.println(sub.name + " " + sup.name); } } class Super{ String name; Super(String s){ name =s ; } }
technology programming languages

  1. Error: Super(java.lang.String) in Super cannot be applied to ()

  2. First Second

  3. Second First

  4. Runtime Exception

Show answer
Correct Option: C

Given: 1. package com.company.application; 2. 3. public class MainClass { 4. public static void main(String[] args) { } 5. } And MainClass exists in the /apps/com/company/application directory. Assume the CLASSPATH environment variable is set to “.“ (current directory). Which two java commands entered at the command line will run MainClass? (Choose two.) A. java MainClass if run from the /apps directory B. java com.company.application.MainClass if run from the /apps directory C. java -classpath /apps com.company.application.MainClass if run from any directory D. java -classpath . MainClass if run from the /apps/com/company/application directory E. java -classpath /apps/com/company/application:. MainClass if run from the /apps directory F. java com.company.application.MainClass if run from the /apps/com/company/application directory

technology programming languages

  1. A

  2. B

  3. C

  4. D

  5. E

  6. F

Show answer
Correct Option: B,C

AI Explanation

To determine which java commands will run the MainClass, we need to consider the CLASSPATH environment variable and the location of the MainClass file. Let's go through each option to determine whether it is correct or incorrect:

Option A) java MainClass if run from the /apps directory - This option is incorrect because the MainClass file is not in the current directory. The command will not be able to find the MainClass file.

Option B) java com.company.application.MainClass if run from the /apps directory - This option is correct because it specifies the fully qualified name of the MainClass and the command is executed from the directory that contains the MainClass file.

Option C) java -classpath /apps com.company.application.MainClass if run from any directory - This option is correct because it specifies the classpath to be the /apps directory, which contains the MainClass file. The command can be executed from any directory.

Option D) java -classpath . MainClass if run from the /apps/com/company/application directory - This option is incorrect because it does not specify the fully qualified name of the MainClass. The command will not be able to find the MainClass file.

Option E) java -classpath /apps/com/company/application:. MainClass if run from the /apps directory - This option is incorrect because it does not specify the fully qualified name of the MainClass. The command will not be able to find the MainClass file.

Option F) java com.company.application.MainClass if run from the /apps/com/company/application directory - This option is incorrect because it does not include the classpath. The command will not be able to find the MainClass file.

The correct answers are B and C. These options specify the fully qualified name of the MainClass and include the correct classpath to locate the MainClass file.

Click the Exhibit button. 10. class Inner { 11. private int x; 12. public void setX( int x) { this.x = x; } 13. public int getX() { return x; } 14. } 15. 16. class Outer { 17. private Inner y; 18. public void setY( Inner y) { this.y = y; } 19. public Inner getY() { return y; } 20. } 21. 22. public class Gamma { 23. public static void main( String[] args) { 24. Outer o = new Outer(); 25. Inner i = new Inner(); 26.int n=10; 27. i.setX(n); 28. o.setY(i); 29. // insert code here 30. System.out.println( o.getY().getX()); 31. } 32. } Which three code fragments, added individually at line 29, produce the output 100? (Choose three.)
technology programming languages

  1. n = 100;

  2. i.setX( 100);

  3. o.getY().setX( 100);

  4. i = new Inner(); i.setX( 100);

  5. o.setY( i); i = new Inner(); i.setX( 100);

  6. i = new Inner(); i.setX( 100); o.setY( i);

Show answer
Correct Option: B,C,F

Given: 1. public class Threads2 implements Runnable { 2. 3. public void nun() { 4. System.out.println(”run.”); 5. throw new RuntimeException(”Problem”); 6. } 7. public static void main(String[] args) { 8. Thread t = new Thread(new Threads2()); 9. t.start(); 10. System.out.println(”End of method.”); 11. } 12. } Which two can be results? (Choose two.) A. java.lang.RuntimeException: Problem B. run. java.lang.RuntimeException: Problem C. End of method. java.lang.RuntimeException: Problem D. End of method. run. java.lang.RuntimeException: Problem E. run. java.lang.RuntimeException: Problem End of method.
technology programming languages

  1. A

  2. B

  3. C

  4. D

  5. E

Show answer
Correct Option: D,E

Given: 1. public class TestString3 { 2. public static void main(String[] args) { 3. // insert code here 5. System.out.println(s); 6. } 7. } Which two code fragments, inserted independently at line 3, generate the output 4247? (Choose two.) A. String s = “123456789”; s = (s-”123”).replace(1,3,”24”) - “89”; B. StringBuffer s = new StringBuffer(”123456789”); s.delete(0,3).replace( 1,3, “24”).delete(4,6); C. StringBuffer s = new StringBuffer(”123456789”); s.substring(3,6).delete( 1 ,3).insert( 1, “24”); D. StringBuilder s = new StringBuilder(”123456789”); s.substring(3,6).delete( 1 ,2).insert( 1, “24”); E. StringBuilder s = new StringBuilder(”123456789”); s.delete(0,3).delete( 1 ,3).delete(2,5).insert( 1, “24”);

technology programming languages

  1. A

  2. B

  3. C

  4. D

  5. E

Show answer
Correct Option: B,E

AI Explanation

To determine which code fragments inserted independently at line 3 generate the output 4247, let's go through each option:

Option A) String s = "123456789"; s = (s-"123").replace(1,3,"24") - "89"; This code will not compile because you cannot subtract a string from another string. Additionally, the replace() method does not have a subtract operator. Therefore, this option is incorrect.

Option B) StringBuffer s = new StringBuffer("123456789"); s.delete(0,3).replace(1,3, "24").delete(4,6); This code fragment will generate the output 4247.

  • The delete(0,3) method deletes the characters from index 0 to index 3 in the string, resulting in "456789".
  • The replace(1,3, "24") method replaces the characters from index 1 to index 3 with "24", resulting in "424789".
  • The delete(4,6) method deletes the characters from index 4 to index 6 in the string, resulting in "4247".

Therefore, this option is correct.

Option C) StringBuffer s = new StringBuffer("123456789"); s.substring(3,6).delete(1 ,3).insert(1, "24"); This code will not generate the output 4247.

  • The substring(3,6) method returns the substring from index 3 to index 6, resulting in "456".
  • The delete(1,3) method deletes the characters from index 1 to index 3 in the substring, resulting in "46".
  • The insert(1, "24") method inserts the string "24" at index 1 in the substring, resulting in "4246".

Therefore, this option is incorrect.

Option D) StringBuilder s = new StringBuilder("123456789"); s.substring(3,6).delete(1,2).insert(1, "24"); This code will not generate the output 4247.

  • The substring(3,6) method returns the substring from index 3 to index 6, resulting in "456".
  • The delete(1,2) method deletes the character at index 1 in the substring, resulting in "46".
  • The insert(1, "24") method inserts the string "24" at index 1 in the substring, resulting in "4246".

Therefore, this option is incorrect.

Option E) StringBuilder s = new StringBuilder("123456789"); s.delete(0,3).delete(1,3).delete(2,5).insert(1, "24"); This code fragment will generate the output 4247.

  • The delete(0,3) method deletes the characters from index 0 to index 3 in the string, resulting in "456789".
  • The delete(1,3) method deletes the characters from index 1 to index 3 in the string, resulting in "479".
  • The delete(2,5) method deletes the characters from index 2 to index 5 in the string, resulting in "47".
  • The insert(1, "24") method inserts the string "24" at index 1 in the string, resulting in "4247".

Therefore, this option is correct.

The correct answers are B and E.

Click the Exhibit button. 1. public class A { 2. public void method1() { 3. B b=new B(); 4. b.method2(); 5. // more code here 6. } 7. } 1. public class B { 2. public void method2() { 3.C c=new C(); 4. c.method3(); 5. // more code here 6. } 7. } 1. public class C { 2. public void method3() { 3. // more code here 4. } 5. } Given: 25. try { 26. A a=new A(); 27. a.method1(); 28. } catch (Exception e) { 29. System.out.print(”an error occurred”); 30. } Which two are true if a NullPointerException is thrown on line 3 of class C? (Choose two.)
technology programming languages

  1. The application will crash.

  2. The code on line 29 will be executed.

  3. The code on line 5 of class A will execute.

  4. The code on line 5 of class B will execute.

  5. The exception will be propagated back to line 27.

Show answer
Correct Option: B,E

Given: 33. try { 34. // some code here 35. } catch (NullPointerException e1) { 36. System.out.print(”a”); 37. } catch (RuntimeException e2) { 38. System.out.print(”b”); 39. } finally { 40. System.out.print(”c”); 41. } What is the result if a NullPointerException occurs on line 34?
technology programming languages

  1. c

  2. a

  3. ab

  4. ac

  5. bc

  6. abc

Show answer
Correct Option: D
  1. Given: 10. class One { 11. public One foo() { return this; } 12. } 13. class Two extends One { 14. public One foo() { return this; } 15. } 16. class Three extends Two { 17. // insert method here 18. } Which two methods, inserted individually, correctly complete the Three class? (Choose two.)
technology programming languages

  1. public void foo() { }

  2. public int foo() { return 3; }

  3. public Two foo() { return this; }

  4. public One foo() { return this; }

  5. public Object foo() { return this; }

Show answer
Correct Option: C,D

Given: 10. public class Fabric 11. public enum Color { 12. RED(0xff0000), GREEN(0x00ff00), BLUE(0x0000ff); 13. private final int rgb; 14. Color( int rgb) { this.rgb = rgb; } 15. public int getRGB() { return rgb; } 16. }; 17. public static void main( String[] argv) { 18. // insert code here 19. } 20. } Which two code fragments, inserted independently at line 18, allow the Fabric class to compile? (Choose two.)

technology programming languages

  1. Color skyColor = BLUE;

  2. Color treeColor = Color.GREEN;

  3. Color purple = new Color( 0xff00ff);

  4. if( RED.getRGB() < BLUE.getRGB() ) {}

  5. Color purple = Color.BLUE + Color.RED;

  6. if( Color.RED.ordinal() < Color.BLUE.ordinal() ) {}

Show answer
Correct Option: B,F

AI Explanation

To answer this question, let's review each of the given options:

Option A) Color skyColor = BLUE; This option assigns the enum constant "BLUE" to the variable "skyColor". This is incorrect because "BLUE" is a member of the "Color" enum and should be accessed as "Color.BLUE".

Option B) Color treeColor = Color.GREEN; This option correctly assigns the enum constant "GREEN" from the "Color" enum to the variable "treeColor". This is a valid way to access enum constants.

Option C) Color purple = new Color(0xff00ff); This option attempts to create a new enum constant using the constructor of the "Color" enum. However, enum constants are predefined and cannot be created using the constructor. This is incorrect.

Option D) if (RED.getRGB() < BLUE.getRGB()) {} This option correctly accesses the "getRGB()" method of the "RED" and "BLUE" enum constants and performs a comparison. This is a valid way to access enum constants and their methods.

Option E) Color purple = Color.BLUE + Color.RED; This option attempts to add the enum constants "BLUE" and "RED". However, enum constants cannot be added together using the "+" operator. This is incorrect.

Option F) if (Color.RED.ordinal() < Color.BLUE.ordinal()) {} This option correctly accesses the "ordinal()" method of the "RED" and "BLUE" enum constants and performs a comparison. This is a valid way to access enum constants and their methods.

Therefore, the correct options are B) Color treeColor = Color.GREEN; and F) if (Color.RED.ordinal() < Color.BLUE.ordinal()).

An Element can be
technology databases

  1. Source file

  2. Directories

  3. Binary files

  4. All the above

Show answer
Correct Option: D