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">
   <h4>Question # 1</h4>
    <div class="qtn">
        <p>What is unboxing?</p>
    </div>
    <div class="ans">
        <p>Unboxing is the reverse of boxing. <span class="hi-yl-b">Converting an object of a wrapper type say an <code class="clazz">Integer</code> to its corresponding primitive <code class="clazz">int</code> value is called unboxing.</span></p>
<b>

```java
    void print(List<Integer> nums) {

        int k;
        for (Integer i : nums) {
            k = i;
            System.out.println(k);
        }
    }
```
</b>
<p>Consider the above method, where the statement <code class="mthd">k = i</code> results in the compiler converting the <code class="clazz">Integer</code> object into its equivalent <code class="clazz">int</code> primitive value.</p>
</div>
</div>

<div class="card">
   # Question # 1
    <div class="qtn">
        <p>What is unboxing?</p>
    </div>
    <div class="ans">
        <p>Unboxing is the reverse of boxing. <span class="hi-yl-b">Converting an object of a wrapper type say an <code class="clazz">Integer</code> to its corresponding primitive <code class="clazz">int</code> value is called unboxing.</span></p>
<b>

```java
    void print(List<Integer> nums) {

        int k;
        for (Integer i : nums) {
            k = i;
            System.out.println(k);
        }
    }
```
</b>
<p>Consider the above method, where the statement <code class="mthd">k = i</code> results in the compiler converting the <code class="clazz">Integer</code> object into its equivalent <code class="clazz">int</code> primitive value.</p>
</div>
</div>

<div>
   # Question # 1
    <div>
        <p>What is unboxing?</p>
    </div>
    <div>
        <p>Unboxing is the reverse of boxing. <span>Converting an object of a wrapper type say an <code>Integer</code> to its corresponding primitive <code>int</code> value is called unboxing.</span></p>
<b>

```java
    void print(List<Integer> nums) {

        int k;
        for (Integer i : nums) {
            k = i;
            System.out.println(k);
        }
    }
```
</b>
<p>Consider the above method, where the statement <code>k = i</code> results in the compiler converting the <code>Integer</code> object into its equivalent <code>int</code> primitive value.</p>
</div>
</div>

This lesson discusses the reverse of Boxing, which is called Unboxing.

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

Unboxing

Question # 1