Java Multithreading Interview Questions and Answers for Freshers - 1

Question: 1

What is a thread?

A thread is a set of instructions executing apart from other threads (with its own stack) but sharing the same memory space (with the same heap).

Question: 2

How can we create a thread in java?

There are two ways to create a thread in java – first by implementing runable interface and then creating a thread object from it and second is to extend the thread class.

Question: 3

What is the difference between user thread and daemon thread?

When we create a thread in java program, it’s known as user thread.

A daemon thread runs in background and doesn’t prevent JVM from terminating.

When there are no user threads running.

JVM shutdown the program and quits.

A child thread created from daemon thread is also a daemon thread.

Question: 4

When is a thread created?

A thread is created by the VM behind the scenes during a call to the start() method.

It begins its life inside the run() method of the thread subclass instance whose start() method as called.

Question: 5

What is daemon thread?

Daemon thread is a low priority thread, which runs intermittently in the back ground doing the garbage collection operation for the java runtime system.