Tag: technology

Questions Related to technology

7 What will be the result of attempting to compile and run the following code? abstract class MineBase { abstract void amethod(); static int i; } public class Mine extends MineBase { public static void main(String argv[]){ int[] ar=new int[5]; for(i=0;i < ar.length;i++) System.out.println(ar[i]); } }
technology programming languages
    1. a sequence of 5 0's will be printed
    1. Error: ar is used before it is initialized
    1. Error Mine must be declared abstract
    1. IndexOutOfBoundes Error
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Correct Option: C

8 What will happen if you attempt to compile and run the following code? Integer ten=new Integer(10); Long nine=new Long (9); System.out.println(ten + nine); int i=1; System.out.println(i + ten);
technology programming languages

  1. a. 19 followed by 20

  2. b. 19 followed by 11

  3. c. Compile time error

  4. d. 10 followed by 1

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Correct Option: A

9 If you run the code below, what gets printed out? String s=new String("Bicycle"); int iBegin=1; char iEnd=3; System.out.println(s.substring(iBegin,iEnd));
technology programming languages

  1. a. Bic

  2. b. ic

  3. c. icy

  4. d. error: no method matching substring(int,char)

Show answer
Correct Option: B
Explanation:

To solve this question, the user needs to understand the concept of substring and character indices.

The given code creates a string object s with value "Bicycle". The variables iBegin and iEnd have been assigned the values 1 and 3, respectively. The substring method is then called on the string object s with two arguments: iBegin and iEnd. The substring method extracts a portion of the string starting at the index specified by iBegin and ending at the index specified by iEnd-1.

Option A is incorrect because the substring method with arguments (1,3) extracts the portion of the string starting at index 1 and ending at index 2. Thus, the output is "Bi".

Option B is correct because the substring method with arguments (1,3) extracts the portion of the string starting at index 1 and ending at index 2. Thus, the output is "ic".

Option C is incorrect because the substring method with arguments (1,3) extracts the portion of the string starting at index 1 and ending at index 2. Thus, the output is "ic", not "icy".

Option D is incorrect because the syntax of the substring method is correct, and there is a matching method signature that takes an int and a char.

Therefore, the answer is:

The Answer is: B. ic

10 What modifiers would be legal at XX in the following code? public class MyClass1 { public static void main(String argv[]){ } /*Modifier at XX */ class MyInner {} }
technology programming languages

  1. a. public

  2. b. private

  3. c. static

  4. d. friend

Show answer
Correct Option: A,B

11 What will the following code print out? public class Oct{ public static void main(String argv[]){ Oct o = new Oct(); o.amethod(); } public void amethod(){ int oi= 012; System.out.println(oi); } }
technology programming languages

  1. A 12

  2. B 012

  3. C 10

  4. D 10.0

Show answer
Correct Option: C
Explanation:

To solve this question, the user needs to know the basics of Java programming language. The code creates an object of the Oct class and then calls the amethod() method, which initializes an integer variable oi with 012 and prints its value to the console.

In Java, leading zero in an integer literal denotes an octal (base-8) number. Therefore, the value 012 is an octal number that represents the decimal value 10.

So, the correct answer is:

The Answer is: C. 10

12 You have these files in the same directory. What will happen when you attempt to compile and run Class1.java if you have not already compiled Base.java //Base.java package Base; class Base{ protected void amethod(){ System.out.println("amethod"); }//End of amethod }//End of class base package Class1; //Class1.java public class Class1 extends Base{ public static void main(String argv[]){ Base b = new Base(); b.amethod(); }//End of main }//End of Class1
technology programming languages

  1. a. Compile Error: Methods in Base not found

  2. b. Compile Error: Unable to access protected method in base class

  3. c. Compilation followed by the output "amethod"

  4. d. Compile error: Superclass Class1.Base of class Class1.Class1 not found

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Correct Option: D

13 Which of the following statements are true?
technology programming languages

  1. a. The elements in a Java array can only be of primitive types, not objects

  2. b. Arrays elements are initialized to default values wherever they are created using the keword new

  3. c. An array may be dynamically resized using the setSize method

  4. d. You can find out the size of an array using the size method

Show answer
Correct Option: B

14 Which of the following are legal statements?
technology programming languages

  1. a float f=1/3;

  2. b int i=1/3;

  3. c float f=1.01;

  4. d double d=999d;

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Correct Option: A,B,D

15 Which of the following are valid statements?
technology programming languages

  1. A System.out.println(1+1);

  2. B int i=2+'2';

  3. C String s="on"+'one';

  4. D byte b=255;

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Correct Option: A,B

16 Which of the following statements are true?

technology programming languages

  1. a. All of the variables in an interface are implicitly static

  2. b. All of the variables in an interface are implicitly final

  3. c. All of the methods in an interface are implicitly abstract

  4. d. A method in an interface can access class level variables

Show answer
Correct Option: A,B,C

AI Explanation

To answer this question, let's go through each option to understand why it is correct or incorrect:

Option A) All of the variables in an interface are implicitly static - This option is true. In an interface, all variables are implicitly static, meaning they belong to the interface itself rather than any specific instance.

Option B) All of the variables in an interface are implicitly final - This option is true. In an interface, all variables are implicitly final, meaning their values cannot be changed once they are assigned.

Option C) All of the methods in an interface are implicitly abstract - This option is true. In an interface, all methods are implicitly abstract, meaning they do not have a body and must be implemented by any class that implements the interface.

Option D) A method in an interface can access class-level variables - This option is false. Methods in an interface can only access variables declared within the interface itself. They cannot access variables from implementing classes or any other classes.

The correct answer is A, B, C. These options are correct because variables in an interface are implicitly static and final, and methods in an interface are implicitly abstract.