The ultimate guide to Java interviews with 300+ real-world questions and answers. Get interview-ready in just a few hours with strategies developed by FAANG engineers.

It’s very common to have interviews testing your knowledge of a programming language you claim to be an expert in.

If you've got an interview coming up on Java soon and need to get up to speed, this is the ideal course for you. You'll refresh your memory on everything from the basics to more advanced functionality you’re likely to be asked about. Even if you're using Java every day, you may not have been exposed to parts of it in some time, so it's always useful to make sure you're updated.

This course features more than 300 of the most commonly asked core Java interview questions that you're likely to face as an experienced software engineer. You'll get to explore questions by topic, as well as see detailed answers for each one, and plenty of live code examples where relevant. Get started today.

The Java Interview Handbook: 300+ Interview Questions

<div class="card">
   # Question # 1
    <div class="qtn">
        <p>What files do we write Java code in?</p>
    </div>
    <div class="ans">
        <p>Java code is written in files with the extension <code class="fext">.java</code></p>
</div>
</div>

<div class="card">
   # Question # 2
    <div class="qtn">
<p>What are .class files?</p>
<p>or</p>
        <p>What is Java bytecode?</p>
    </div>
    <div class="ans">
        <p>The java compiler compiles the <code class="fext">.java</code> files into <code class="fext">.class</code> files. The <code class="fext">.class</code> files contain what is known as the <b><i>java bytecode</i></b>. Then the bytecode can be run by the JVM. <span class="hi-yl-b">Java bytecode is the instruction set of the Java virtual machine.</span></p>
</div>
</div>


<div class="card">
   # Question # 3
    <div class="qtn">
        <p>What are .jar files?</p>
    </div>
    <div class="ans">
        <p>A JAR (Java Archive) is a package file format used to aggregate many Java class files and associated metadata and resources (text, images, etc.) into one file for distribution. A jar file is built on the ZIP format and typically has a .jar file extension. The jar tool can be used to create <code class="fext">.jar</code> file.</p>
</div>
</div>

<div>
   # Question # 1
    <div>
        <p>What files do we write Java code in?</p>
    </div>
    <div>
        <p>Java code is written in files with the extension <code>.java</code></p>
</div>
</div>

<div>
   # Question # 2
    <div>
<p>What are .class files?</p>
<p>or</p>
        <p>What is Java bytecode?</p>
    </div>
    <div>
        <p>The java compiler compiles the <code>.java</code> files into <code>.class</code> files. The <code>.class</code> files contain what is known as the <b><i>java bytecode</i></b>. Then the bytecode can be run by the JVM. <span>Java bytecode is the instruction set of the Java virtual machine.</span></p>
</div>
</div>


<div>
   # Question # 3
    <div>
        <p>What are .jar files?</p>
    </div>
    <div>
        <p>A JAR (Java Archive) is a package file format used to aggregate many Java class files and associated metadata and resources (text, images, etc.) into one file for distribution. A jar file is built on the ZIP format and typically has a .jar file extension. The jar tool can be used to create <code>.jar</code> file.</p>
</div>
</div>

Common file types and tools used in Java development.

Java Ecosystem

Methods

Classes

Interfaces

Inheritance

Lambda Expressions

Generics

Multi-Threading

Memory Management

Collections

Exceptions

Reflection

Serialization

Miscellaneous Topics

Java in Practice

Patterns

The End

Java Tools & Files

Question # 1

Question # 2

Question # 3