30 Java Coding Questions To Assess Programming Skills part 1 ~ foundjava

It’s not often that a Java developer gets through a programming interview without being evaluated for his coding skills. Many IT companies have the Java coding skill test hosted within their local intranet. And some still ask the candidates to prove their coding ability via an offline skill assessment method. Hence, a programmer should prepare himself for such faceoffs and keep looking for challenging Java coding questions.

The objective of such a coding skill assessment test is not to measure your knowledge of language syntax or the no. of functions you remember. But it’s for analyzing the programming logic you’ll apply and the design approach you choose. That’s why most of the time you’ll be given small coding snippets to brainstorm and figuring out the correct output. There are chances that you get a code with errors. And the interviewer would expect you to be smart enough to judge the coding error.

Wait for a while. If you are assuming that the interviewer will ignore the language semantics and other high-level characteristics, then it’s not going to happen. These are core concepts which even you require while writing and optimizing the code. For example, in Java, Serialization is an important subject to understand. A Java developer should know how to serialize or deserialize a class. And he should be wise enough to decide where to apply serialization.

Some more concepts that one should be comfortable with are Strings, Collection framework, and Multithreading in Java. You will need all of them in your arsenal if wish to be a real Java programmer. Also, believe that whatever knowledge we learn today becomes the bridge for getting on to the next level of technologies like J2EE, Maven, and Spring MVC.

Coming back to the topic of the day, the Thirty Java Coding Questions Challenge that we’ve prepared after doing a lot of filtering. All these questions would make you practice your Java skills and test your understanding of programming concepts and logical skills.

30 Java Coding Questions To Assess Programming Skills.

Question-1. Which Of The Following Would The Below Java Coding Snippet Return As Its Output?

Java

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class Super {     public int index = 1; } class App extends Super {     public App(int index) {         index = index;     }     public static void main(String args[]) {         App myApp = new App(10);         System.out.println(myApp.index);     } }

A. 0
B. 10
C. 1
D. Compile time error

Check correct option.

Question-2. Which Of The Following Combinations Would The Below Java Coding Snippet Print?

Java

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class TestApp {     protected int x, y; } class Main {     public static void main(String args[]) {         TestApp app = new TestApp();         System.out.println(app.x + " " + app.y);     } }

A. 0 1
B. 1 0
C. 0 0
D. null null

Check correct option.

Question-3. What Would Be The Outcome Of Following Java Coding Snippet?

Java

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class TestApp {     public static void main(String[] args) {         for (int index = 0; 1; index++) {             System.out.println("Welcome");             break;         }     } }

A. Welcome
B. Welcome Welcome
C. Type mismatch error
D. Run infinite-times

Check correct option.

Question-4. What Would The Below Java Coding Snippet Print?

Java

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class TestApp {     public static void main(String[] args) {         for (int index = 0; true; index++) {             System.out.println("Welcome");             break;         }     } }

A. Welcome
B. None
C. Type mismatch error
D. Run infinite times

Check correct option.

Question-5. Which Of The Following Values Would The Below Java Coding Snippet Print In Results?

Java

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class TestApp {     int i[] = { 0 };     public static void main(String args[]) {         int i[] = { 1 };         alter(i);         System.out.println(i[0]);     }     public static void alter(int i[]) {         int j[] = { 2 };         i = j;     } }

A. 0
B. 1
C. 2
D. Compilation error

Check correct option.

Question-6. Which Of The Following Is The Result Of The Following Java Code?

Java

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class TestApp {     String args[] = { "1", "2" };     public static void main(String args[]) {         if (args.length > 0)             System.out.println(args.length);     } }

A. The program compiles but prints nothing.
B. The program fails to compile.
C. The program compiles and prints 2.
D. The program compiles and prints 0.

Check correct option.

Question-7. What Is The Result Of The Following Java Coding Snippet?

Java

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class TestApp {     public static void main() {         int odd = 1;         if (odd) {             System.out.println("odd");         } else {             System.out.println("even");         }     } }

A. odd
B. even
C. Run-time exception
D. Type mismatch error

Check correct option.

Question-8. What Would The Following Function Yield When Called?

Java

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public void test(boolean a, boolean b) {     if (a) {         System.out.println("A");     } else if (a && b) {         System.out.println("A && B");     } else {         if (!b) {             System.out.println("!B");         } else {             System.out.println("None");         }     } }

A. If a and b both are true, then the output is “A && B”.
B. If a is true and b is false, then the output is “!B”.
C. If a is false and b is true, then the output is “None”.
D. If a and b both are false, then the output is “None”.

Check correct option.

Question-9. What Would The Following Java Coding Snippet Return As Its Output?

Java

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class TestApp {     public static void main(String[] args) {         class Tutorial {             public String name;             public Tutorial(String tutorial) {                 name = tutorial;             }         }         Object obj = new Tutorial("Java Quiz");         Tutorial tutorial = (Tutorial) obj;         System.out.println(tutorial.name);     } }

A. An exception occurs while instantiating Tutorial class.
B. It’ll print “Java Quiz”.
C. The program will print null.
D. Compilation error at line number 13.

Check correct option.

Question-10. What Does The Following Java Coding Snippet Print?

Java

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import java.io.CharArrayReader; import java.io.IOException; class TestApp {     public static void main(String[] args) {         String obj = "abcdef";         int length = obj.length();         char c[] = new char[length];         obj.getChars(0, length, c, 0);         CharArrayReader io_1 = new CharArrayReader(c);         CharArrayReader io_2 = new CharArrayReader(c, 0, 3);         int i;         try {             while ((i = io_1.read()) != -1) {                 System.out.print((char) i);             }         } catch (IOException e) {             e.printStackTrace();         }     } }

A. abc
B. abcd
C. abcde
D. abcdef

Check correct option.

Question-11. What Will Be The Output Of Following Java Coding Snippet?

Java

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import java.io.CharArrayReader; import java.io.IOException; class TestApp {     public static void main(String[] args) {         String obj = "abcdef";         int length = obj.length();         char c[] = new char[length];         obj.getChars(0, length, c, 0);         CharArrayReader io_1 = new CharArrayReader(c);         CharArrayReader io_2 = new CharArrayReader(c, 0, 3);         int i;         try {             while ((i = io_2.read()) != -1) {                 System.out.print((char) i);             }         } catch (IOException e) {             e.printStackTrace();         }     } }

A. abc
B. abcd
C. abcde
D. abcdef

Check correct option.

Question-12. What Would The Following Java Coding Snippet Return?

Java

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import java.io.CharArrayReader; import java.io.IOException; class TestApp {     public static void main(String[] args) {         String obj = "abcdef";         int length = obj.length();         char c[] = new char[length];         obj.getChars(0, length, c, 0);         CharArrayReader io_1 = new CharArrayReader(c);         CharArrayReader io_2 = new CharArrayReader(c, 1, 4);         int i, j;         try {             while ((i = io_1.read()) == (j = io_2.read())) {                 System.out.print((char) i);             }         } catch (IOException e) {             e.printStackTrace();         }     } }

A. abc
B. abcd
C. abcde
D. abcdef
E. Nothing would get printed.

Check correct option.

Question-13. What Is The Outcome Of The Below Java Code?

Java

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class TestApp {     public static void main(String args[]) {         System.out.println(test());     }     static float test() {         static float x = 0.0;         return ++x;     } }

A. 0.0
B. 1
C. 1.0
D. Compile time error

Check correct option.

Question-14. What Does The Following Java Coding Snippet Yield?

Java

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class TestApp {     static int index = 0;     public static void main(String args[]) {         System.out.println(test());     }     int test() {         int index = 1;         return index;     } }

A. 0 
B. 1 
C. Run-time error at line number 6 
D. Compile time error

Check correct option.

Question-15. Which Of The Following Is The Result Of The Below Java Coding Snippet?

Java

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class TestApp {       public static void main(String args[]) {         int bits;           bits = -3 >> 1;         bits = bits >>> 2;         bits = bits << 1;         System.out.println(bits);     } }

A. 1 
B. 7 
C. -2147483646 
D. 2147483646

Check correct option.