Update java-multiple-choice-questions-answers.md

Author: learning-zone

java-multiple-choice-questions-answers.md

@@ -1,47 +1,47 @@
-## Java Multiple Choice Questions 
+# Java Multiple Choice Questions 
 
 
-#### Q. Which of the follwing below live on the heap in java?
+## Q. Which of the follwing below live on the heap in java?
 * Class
 * Instance variable
 * Method
 * Object
 ```
 Object
 ```
-#### Q. Which of the following interface is used to declare core methods in java?
+## Q. Which of the following interface is used to declare core methods in java?
 * Set
 * EventListner
 * Collection
 * Comparator
 ```
 Collection
 ```
-#### Q. Which of these interface handle sequences?
+## Q. Which of these interface handle sequences?
 * Set
 * List
 * Comparator
 * Collection
 ```
 List
 ```
-#### Q. Which of this interface must contain a unique element?
+## Q. Which of this interface must contain a unique element?
 * Set
 * List
 * Array
 * Collection
 ```
 Set
 ```
-#### Q. Which of the following declarations does not compile?
+## Q. Which of the following declarations does not compile?
 A. double num1, int num2 = 0;  
 B. int num1, num2;  
 C. int num1, num2 = 0;  
 D. int num1 = 0, num2 = 0;  
 ```
 A. double num1, int num2 = 0;
 ```
-#### Q. What is the output of following program?
+## Q. What is the output of following program?
 ```java
 public class Test {
 
@@ -64,7 +64,7 @@ Output
     <b><a href="#">↥ back to top</a></b>
 </div>
 
-#### Q. What is the output of following program?
+## Q. What is the output of following program?
 ```java
 import java.util.ArrayList;
 public class Test {
@@ -83,7 +83,7 @@ Output
 ```
 [1, 1, 1]
 ```
-#### Q. What is the output of following program?
+## Q. What is the output of following program?
 ```java
 public class Test {
 
@@ -101,15 +101,15 @@ Exception in thread "main" java.lang.Error: Unresolved compilation problem:
 
 	at Test.main(Test.java:5)
 ```
-#### Q. Which statement about a valid .java file is true?
+## Q. Which statement about a valid .java file is true?
 **A.** It can only contain one class declaration.  
 **B.** It can contain one pulic class declaration and one public interface definition.  
 **C.** It must define at least one public class.  
 **D.** It may define at most one public class.  
 ```
 Answer: D
 ```
-#### Q. What is the output of following program?
+## Q. What is the output of following program?
 ```java
 public class Test {  
 
@@ -134,7 +134,7 @@ Exception in thread "main" java.lang.Error: Unresolved compilation problem:
     <b><a href="#">↥ back to top</a></b>
 </div>
 
-#### Q. What is the output of following program?
+## Q. What is the output of following program?
 ```java
 public class Test{  
 
@@ -157,7 +157,7 @@ Output
 ```
 [2 5]
 ```
-#### Q. What is the output of following program?
+## Q. What is the output of following program?
 ```java
 public class Test 
 {
@@ -183,7 +183,7 @@ Exception in thread "main" java.lang.Error: Unresolved compilation problem:
     <b><a href="#">↥ back to top</a></b>
 </div>
 
-#### Q. What is the output of following program?
+## Q. What is the output of following program?
 ```java
 public class Test 
 {  	
@@ -214,7 +214,7 @@ Output
 a : 2
 J : 2
 ```
-#### Q. Which of the following declarations does not compile?
+## Q. Which of the following declarations does not compile?
 A. double num1, int num2 = 0;  
 B. int num1, num2;  
 C. int num1, num2 = 0;  
@@ -224,7 +224,7 @@ A. double num1, int num2 = 0;
 ```
 **Explanation**: A. Option A does not compile because Java does not allow declaring different types as part of the same declaration. 
 
-#### Q. What is the output of the following?
+## Q. What is the output of the following?
 ```java
 public static void main(String... args) {
    String chair, table = "metal";
@@ -245,15 +245,15 @@ D. The code does not compile
     <b><a href="#">↥ back to top</a></b>
 </div>
 
-#### Q. Which is correct about an instance variable of type String?
+## Q. Which is correct about an instance variable of type String?
 A. It defaults to an empty string.  
 B. It defaults to null.  
 C. It does not have a default value.  
 D. It will not compile without initializing on the declaration line  
 ```
 B. It defaults to null.  
 ```
-#### Q. How many of the following methods compile?
+## Q. How many of the following methods compile?
 ```java
 public class Test 
 {
@@ -282,15 +282,15 @@ C. Two
 ```
 **Explanation**: Objects have instance methods while primitives do not. Since int is a primitive, you cannot call instance methods on it. Integer and String are both objects and have instance methods.
 
-#### Q. Which of the following does not compile?
+## Q. Which of the following does not compile?
 A. int num = 999;  
 B. int num = 9_9_9;  
 C. int num = _9_99;  
 D. None of the above; they all compile.  
 ```
 C. int num = _9_99; 
 ```
-#### Q. Which is the first line to trigger a compiler error?
+## Q. Which is the first line to trigger a compiler error?
 ```java
 double d1 = 5f; // p1
 double d2 = 5.0; // p2
@@ -309,7 +309,7 @@ D. P4
     <b><a href="#">↥ back to top</a></b>
 </div>
 
-#### Q. How many instance initializers are in this code?
+## Q. How many instance initializers are in this code?
 ```java
 public class Bowling {
  { 
@@ -333,7 +333,7 @@ D. Three
 ```
 C. Two
 ```
-#### Q. What is true of the finalize() method?
+## Q. What is true of the finalize() method?
 A. It may be called zero or one times.  
 B. It may be called zero or more times.  
 C. It will be called exactly once.  
@@ -343,15 +343,15 @@ A. It may be called zero or one times.
 ```
 **Explanation**: The `finalize()` method may not be called, such as if your program crashes. However, it is guaranteed to be called no more than once.
 
-#### Q. Which of the following is true about primitives?
+## Q. Which of the following is true about primitives?
 A. You can call methods on a primitive.  
 B. You can convert a primitive to a wrapper class object simply by assigning it.  
 C. You can convert a wrapper class object to a primitive by calling valueOf().  
 D. You can store a primitive directly into an ArrayList.  
 ```
 B. You can convert a primitive to a wrapper class object simply by assigning it.
 ```
-#### Q. What is the output of the following?
+## Q. What is the output of the following?
 ```java
 Integer integer = new Integer(4);
 System.out.print(integer.byteValue());
@@ -370,7 +370,7 @@ C. The code does not compile.
     <b><a href="#">↥ back to top</a></b>
 </div>
 
-#### Q. Which two primitives have wrapper classes that are not merely the name of the primitive with an uppercase letter?
+## Q. Which two primitives have wrapper classes that are not merely the name of the primitive with an uppercase letter?
 A. byte and char  
 B. byte and int  
 C. char and int  
@@ -380,7 +380,7 @@ C. char and int
 ```
 **Explanation**: The wrapper class for int is Integer and the wrapper class for char is Character. All other primitives have the same name. For example, the wrapper class for boolean is Boolean.
 
-#### Q. How do you force garbage collection to occur at a certain point?
+## Q. How do you force garbage collection to occur at a certain point?
 A. Call System.forceGc()  
 B. Call System.gc()  
 C. Call System.requireGc()  
@@ -390,7 +390,7 @@ D. None of the above
 ```
 **Explanation**: While you can suggest to the JVM that it might want to run a garbage collection cycle, the JVM is free to ignore your suggestion.
 
-#### Q. How many of the String objects are eligible for garbage collection right before the end of the main method?
+## Q. How many of the String objects are eligible for garbage collection right before the end of the main method?
 ```java
 public static void main(String[] fruits) {
   String fruit1 = new String("apple");
@@ -410,7 +410,7 @@ C. Two
 ```
 **Explanation**: All three references point to the String apple. This makes the other two String objects eligible for garbage collection.
 
-#### Q. Which of the following does not compile?
+## Q. Which of the following does not compile?
 A. double num = 2.718;  
 B. double num = 2._718;  
 C. double num = 2.7_1_8;  
@@ -423,7 +423,7 @@ B. double num = 2._718;
     <b><a href="#">↥ back to top</a></b>
 </div>
 
-#### Q. Which of the following is the output of this code, assuming it runs to completion?
+## Q. Which of the following is the output of this code, assuming it runs to completion?
 ```java
 public class Toy {
   public void play() {
@@ -450,7 +450,7 @@ B. play-play-
 ```
 **Explanation**: If there was a finalize() method, this would be a different story. However, the method here is finalizer. Tricky! That’s just a normal method that doesn’t get called automatically. Therefore clean is never output.
 
-#### Q. What is the value of tip after executing the following code snippet?
+## Q. What is the value of tip after executing the following code snippet?
 ```java
 int meal = 5;
 int tip = 2;
@@ -465,7 +465,7 @@ A. 1
 ```
 **Explanation**: In ternary expressions, only one of the two right-most expressions are evaluated. Since `meal>6` is false, `––tip` is evaluated and `++tip` is skipped. The result is that `tip` is changed from 2 to 1.
 
-#### Q. What is the output of the following application?
+## Q. What is the output of the following application?
 ```java
 String john = "john";
 String jon = new String(john);