Tag: technology

Questions Related to technology

Given: 11. public class Ball { 12. public enum Color { RED, GREEN, BLUE }; 13. public void foo() { 14. // insert code here 15. { System.out.println(c); } 16. } 17. } Which code inserted at line 14 causes the foo method to print RED, GREEN, and BLUE?
technology programming languages

  1. for( Color c : Color.values())

  2. for( Color c = RED; c <= BLUE; c++)

  3. for( Color c; c.hasNext() ; c.next())

  4. for( Color c = Color[0]; c <= Color[2]; c++)

Show answer
Correct Option: A
Explanation:

To solve this question, the user needs to know how to iterate through an enum in Java.

Option A is correct because it uses the values() method provided by the Color enum to iterate through all the possible values, and prints each one to the console.

Option B is incorrect because it treats the Color enum as if it were an integer, which it is not. It also uses an incorrect syntax for the for loop header.

Option C is incorrect because there is no hasNext() method for enums in Java. This is a method provided by the Iterator interface, which enums do not implement.

Option D is incorrect because there is no Color[0] syntax in Java. Additionally, the enum values are not guaranteed to be stored in an array in the order they are defined.

Therefore, the correct answer is:

The Answer is: A. for( Color c : Color.values())

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

Show answer
Correct Option: B,D

Given: 11. public enum Title { 12. MR(”Mr.”), MRS(”Mrs.”), MS(”Ms.”); 13. private final String title; 14. private Title(String t) { title = t; } 15. public String format(String last, String first) { 16. return title + “ “ + first + “ “ + last; 17. } 18. } 19. public static void main(String[] args) { 20. System.out.println(Title.MR.format(”Doe”, “John”)); 21. } What is the result?
technology programming languages

  1. Mr. John Doe

  2. An exception is thrown at runtime

  3. Compilation fails because of an error in line 12

  4. Compilation fails because of an error in line 15

Show answer
Correct Option: A

Given: 11. public static void main(String[] args) { 12. Object obj =new int[] { 1,2,3 }; 13. int[] someArray = (int[])obj; 14. for (int i: someArray) System.out.print(i +“ “) 15. } ‘What is the result?

technology programming languages

  1. 1 2 3

  2. Compilation fails because of an error in line 12.

  3. Compilation fails because of an error in line 13

  4. Compilation fails because of an error in line 14

Show answer
Correct Option: A
Explanation:

To solve this question, the user needs to know about arrays and casting in Java. The code initializes an Object obj to an array of integers with values 1, 2, and 3. It then casts the object to an array of integers and assigns it to the someArray variable. Finally, it uses a for-each loop to print out each element of the someArray array.

Now, let's go through each option and explain why it is right or wrong:

A. 1 2 3: This option is correct. The code initializes an array of integers with values 1, 2, and 3, casts it to an array of integers, and then prints out each element of the array using a for-each loop. This results in the output "1 2 3".

B. Compilation fails because of an error in line 12: This option is incorrect. Line 12 initializes an object to an array of integers, which is allowed in Java. There is no compilation error in this line.

C. Compilation fails because of an error in line 13: This option is incorrect. Line 13 casts the obj object to an array of integers, which is also allowed in Java. There is no compilation error in this line.

D. Compilation fails because of an error in line 14: This option is incorrect. Line 14 uses a for-each loop to print out each element of the someArray array, which is also allowed in Java. There is no compilation error in this line.

Therefore, the answer is:

The Answer is: A. 1 2 3

Given: 10. class Foo { 11. static void alpha() { /* more code here / } 12. void beta() { / more code here */ } 13. } Which two are true? (Choose two.)
technology programming languages

  1. Foo.beta() is a valid invocation of beta().

  2. Foo.alpha() is a valid invocation of alpha().

  3. Method beta() can directly call method alpha().

  4. Method alpha() can directly call method beta().

Show answer
Correct Option: B,C

A programmer needs to create a logging method that can accept an arbitrary number of arguments. For example, it may be called in these ways: logIt(”log message 1 “); logIt(”log message2”,”log message3”); logIt(”log message4”, “log message5”, “log message6); Which declaration satisfies this requirement?
technology programming languages

  1. public void logIt(String * msgs)

  2. public void logIt(String [] msgs)

  3. public void logIt(String... msgs)

  4. public void logIt(String msg1, String msg2, String msg3)

Show answer
Correct Option: C

A programmer is designing a class to encapsulate the information about an inventory item. A JavaBeans component is needed to do this. The Inventoryltem class has private instance variables to store the item information: 10. private int itemId; 11. private String name; 12. private String description; Which method signature follows the JavaBeans naming standards for modifying the itemld instance variable?
technology programming languages

  1. itemID(int itemId)

  2. update(int itemId)

  3. setItemId(int itemId)

  4. mutateItemId(int itemId)

Show answer
Correct Option: C
Explanation:

To solve this question, the user needs to understand the naming conventions used in JavaBeans to create setter methods for private instance variables.

According to JavaBeans conventions, setter methods for private instance variables should be named in the format setVariableName. Therefore, the correct method signature to modify the itemId instance variable in the Inventoryltem class should be:

C. setItemId(int itemId)

Option A: itemID(int itemId) is not following the JavaBeans naming standards for setter methods. The method name should start with the prefix set followed by the variable name.

Option B: update(int itemId) does not follow the JavaBeans naming conventions. The method name should start with the prefix set followed by the variable name.

Option D: mutateItemId(int itemId) is not a standard JavaBeans naming convention. The method name should start with the prefix set followed by the variable name.

Therefore, the correct answer is:

The Answer is: C. setItemId(int itemId)

Click the Exhibit button. 1. public class A { 2. 3. private int counter = 0; 4. 5. public static int getInstanceCount() { 6. return counter; 7. } 8. 9. public A() { 10. counter++; 11. } 12. 13. } Given this code from Class B: 25.A a1 =new A(); 26. A a2 =new A(); 27. A a3 =new A(); 28. System.out.printIn(A.getInstanceCount() ); What is the result?
technology programming languages

  1. Compilation of class A fails

  2. Line 28 prints the value 3 to System.out

  3. Line 28 prints the value 1 to System.out.

  4. A runtime error occurs when line 25 executes

Show answer
Correct Option: A

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 Object foo() { return this; }

Show answer
Correct Option: C,D

Given: 10. class One { 11. void foo() {} 12. } 13. class Two extends One { 14. //insert method here 15. } Which three methods, inserted individually at line 14, will correctly complete class Two? (Choose three.)
technology programming languages

  1. int foo() { /* more code here */ }

  2. void foo() { /* more code here */ }

  3. public void foo() { /* more code here */ }

  4. protected void foo() { /* more code here */ }

Show answer
Correct Option: B,C,D