50 Java Language MCQs with Answers

Question 31

Which of the following is/are advantages of packages?

• Packages avoid name clashes
• Classes, even though they are visible outside their package, can have fields visible to packages only
• We can have hidden classes that are used by the packages, but not visible outside.
• All of the above

Question 32

Predict the output of following Java program

Java

// Note static keyword after import.
import static java.lang.System.*;
  
class StaticImportDemo
{
   public static void main(String args[])
   {      
        out.println(\"GeeksforGeeks\");
   }
}

• Compiler Error
• Runtime Error
• GeeksforGeeks
• None of the above

Question 33

Which of the following statement(s) is/are TRUE regarding Java Servlets? (a) A Java Servlet is a server-side component that runs on the web server and extends the capabilities of a server. (b) A Servlet can use the user interface classes like AWT or Swing.

• Only (a) is TRUE.

• Only (b) is TRUE.

• Both (a) and (b) are TRUE.

• Neither (a) nor (b) is TRUE.

Question 34

Which one of the following is correct?

• Java applets can not be written in any programming language
• An applet is not a small program
• An applet can be run on its own
• Applets are embedded in another applications

Question 35

What is the output of the following JAVA program ?

class simple
{
public static void main(String[ ] args)
{
simple obj = new simple( );
obj.start( );
}
void start( )
{
long [ ] P= {3, 4, 5};
long [ ] Q= method (P);
System.out.print (P[0] + P[1] + P[2]+”:”);
System.out.print (Q[0] + Q[1] + Q[2]);
}
long [ ] method (long [ ] R)
{
R [1]=7;
return R;
}
} //end of class

• 12 : 15
• 15 : 12
• 12 : 12
• 15 : 15

Question 36

What is the output of the following JAVA program ?

Java

Class Test {
    public static void main(String[] args) {
        Test obj = new Test();
        obj.start();
    }
    void start() {
        String stra = ”do”;
            String strb = method(stra);
        System.out.print(“: ”+stra + strb);
    }
    String method(String stra) {
        stra = stra + ”good”;
        System.out.print(stra);
        return“ good”;
    }
}

• dogood : dogoodgood
• dogood : gooddogood
• dogood : dodogood
• dogood : dogood

Question 37

Java uses threads to enable the entire environment to be ______.

• Symmetric
• Asymmetric
• Synchronous
• Asynchronous

Question 38

In Java, when we implement an interface method, it must be declared as:

• Private
• Protected
• Public
• Friend

Question 39

Predict the output of following Java program

Java

class Test {
  int i;
} 
class Main {
  public static void main(String args[]) { 
      Test t = new Test(); 
      System.out.println(t.i);
   } 
}

• garbage value
• 0
• compiler error
• runtime error

Question 40

Study the following program:

// precondition: x>=0
public void demo(int x)
{
    System.out.print(x % 10);
    if (x % 10 != 0) {
        demo(x / 10);
    }
    System.out.print(x % 10);
}

Which of the following is printed as a result of the call demo(1234)?

• 1441

• 3443

• 12344321

• 4321001234