PRUEBA DE JAVA MASTERY

What are the primitive data types in Java?

• object

• string

• array

• int, double, float, boolean, char, byte, short, long

Explain the difference between if-else and switch statements in Java.

• The if-else statement is used for string comparisons, while the switch statement is used for integer comparisons.

• The if-else statement is based on boolean expressions, while the switch statement is based on integral types or enumerated types.

• Switch statements are more efficient than if-else statements in terms of execution speed.

• If-else statements can handle multiple conditions, but switch statements can only handle two conditions.

What is inheritance in Java and how is it implemented?

• Inheritance in Java is implemented using the 'include' keyword.

• Inheritance in Java is implemented using the 'extends' keyword.

• Inheritance in Java is implemented using the 'inherit' keyword.

• Inheritance in Java is implemented using the 'inheritance' keyword.

How does exception handling work in Java? Provide an example.

• try { // code that may throw an exception } catch (ExceptionType e) { // handle the exception }

• try { // code that may throw an exception } catch (Exception e) { // handle the exception } finally { // code that should always run }

• try { // code that may not throw an exception } catch (ExceptionType e) { // handle the exception } finally { // code that should always run }

• try { // code that may throw an exception } catch (ExceptionType e) { // handle the exception } finally { // code that should always run }

What are the different types of collections in Java?

• List, Set, Queue, Map

• Array

• Tuple

• Stack

Explain the concept of multithreading in Java.

• Multithreading in Java allows for sequential execution of threads within a single process.

• Multithreading in Java enables concurrent execution of multiple threads within a single process, allowing for efficient resource utilization and improved performance.

• Multithreading in Java is only applicable to single-threaded applications.

• Multithreading in Java hinders resource utilization and degrades performance.

What is the difference between == and equals() method in Java?

• == compares content, equals() compares reference

• == compares reference, equals() compares content

• == is used for strings, equals() is used for integers

• == compares values, equals() compares references

• == checks for null values, equals() does not

How do you create an object in Java?

• new ClassName();

• ClassName obj = new ClassName();

• Object obj = new Object();

• createObject();

What is the purpose of the synchronized keyword in Java?

• To improve code readability by highlighting important sections

• To control access to critical sections of code and prevent race conditions in multi-threaded environments.

• To automatically generate documentation for the code

• To optimize memory usage in Java applications

Explain the concept of polymorphism in Java.

• Polymorphism in Java is limited to static methods

• Polymorphism in Java is the ability of a single method to perform different actions based on the object it is called on. It is achieved through method overriding and method overloading.

• Polymorphism in Java is only achieved through method overloading

• Polymorphism in Java is the ability to use multiple inheritance