Signiwis Technologies Java Developer Interview Questions and Answers

Multithreading is a programming technique that allows concurrent execution of two or more threads for improved performance.

• Multithreading enables parallel execution, improving application responsiveness.

• Java provides built-in support for multithreading through the Thread class and Runnable interface.

• Example: A web server can handle multiple client requests simultaneously using threads.

• Synchronization is crucial to prev...read more

JavaMail is an API for sending and receiving emails in Java applications, supporting various protocols like SMTP, IMAP, and POP3.

• JavaMail API allows developers to send and receive emails programmatically.

• It supports multiple protocols: SMTP for sending, IMAP and POP3 for receiving.

• Example of sending an email using JavaMail: Properties props = new Properties(); props.put('mail.smtp.host', 'smtp.example.com'); ...read more

Yes, the size of an int in Java is indeed 4 bytes (32 bits).

• An int in Java can hold values ranging from -2,147,483,648 to 2,147,483,647.

• The size of an int can be confirmed using the 'Integer.SIZE' constant in Java.

• Using 'Integer.BYTES' will give the size of an int in bytes.

Yes, the default value of an int in Java is 0.

• In Java, when an int variable is declared but not initialized, it will have a default value of 0.

• For example, int num; will have a default value of 0.

• This default value is assigned by the Java Virtual Machine (JVM) when memory is allocated for the variable.

The static keyword in Java is used to create class-level variables and methods that can be accessed without creating an instance of the class.

• Static variables are shared among all instances of a class.

• Static methods can be called without creating an instance of the class.

• Static blocks are used to initialize static variables.

• Static keyword can also be used to create static nested classes.