Konark Polytubes Interview Questions and Answers

String buffer is synchronized and thread-safe, while string builder is not synchronized and faster.

• String buffer is synchronized, making it thread-safe for use in multi-threaded environments.

• String builder is not synchronized, providing better performance in single-threaded applications.

• String builder is faster than string buffer due to lack of synchronization overhead.

• Example: StringBuffer sb = new StringBuffer(); StringBuilder sb = new StringBuilder();

There are two types of exceptions in Java: checked exceptions and unchecked exceptions.

• Checked exceptions are checked at compile time and must be handled using try-catch or throws keyword.

• Unchecked exceptions are not checked at compile time and include RuntimeException and its subclasses.

• Examples of checked exceptions include IOException, SQLException, and ClassNotFoundException.

• Examples of unchecked exceptions include NullPointerException, ArrayIndexOutOfBoundsException, and...read more

The 4 principles of OOP are Inheritance, Encapsulation, Abstraction, and Polymorphism.

• Inheritance allows a class to inherit properties and behavior from another class.

• Encapsulation restricts access to certain components within a class, protecting the data.

• Abstraction hides complex implementation details and only shows the necessary features.

• Polymorphism allows objects to be treated as instances of their parent class.

Strings are immutable in order to ensure data integrity and security.

• Immutable strings prevent accidental data modification, ensuring data integrity.

• Immutable strings enhance security by preventing unauthorized access or tampering.

• Immutable strings allow for more efficient memory management and optimization.

• Example: 'Hello' cannot be changed to 'Hella' directly, a new string must be created.

JDK includes JRE and development tools, while JRE includes only the Java Runtime Environment.

• JDK stands for Java Development Kit, which includes JRE and development tools like compilers and debuggers.

• JRE stands for Java Runtime Environment, which includes JVM and libraries necessary to run Java applications.

• JVM stands for Java Virtual Machine, which is responsible for executing Java bytecode.

• JDK is used for developing Java applications, while JRE is used for running Java appl...read more

Linear search is a simple searching algorithm that sequentially checks each element in a list until a match is found.

• Iterate through each element in the list

• Compare the current element with the target value

• Return the index if a match is found, otherwise return -1

Operator overloading allows operators to be redefined for user-defined types in Java.

• Operator overloading is not supported in Java as it can lead to ambiguity and confusion.

• Java does not allow custom operators to be defined or existing operators to be overloaded.

• Instead of operator overloading, Java provides method overloading where methods with the same name but different parameters can be defined.