Wrapper Classes: Integer and Double
Sophie Anderson
3 min read
Listen to this study note
Study Guide Overview
This guide covers wrapper classes and autoboxing in Java. It explains the purpose of wrapper classes (like Integer and Double) for primitive types (like int and double), including their use with collections and methods. The guide also discusses constructors and important methods associated with the Integer wrapper class.
#AP Computer Science A: Wrapper Classes - Your Ultimate Study Guide 🚀
Hey there, future AP Computer Science A rockstar! Let's break down wrapper classes and autoboxing. This guide is designed to be your go-to resource the night before the exam, so let's make every minute count!
#Introduction to Wrapper Classes
You're familiar with primitive data types like int and double, but did you know that Integer and Double are classes? Yes, capitalization matters! These are called wrapper classes because they wrap primitive types into objects.
#Why Use Wrapper Classes?
- Object Requirement: Some methods only accept objects as parameters, not primitive types. Wrapper classes allow you to pass primitive data as objects. This is super useful when working with collections (like ArrayLists) or methods that are designed to work with objects.
- Methods: Wrapper classes provide handy methods to operate on primitive values.
- Null Values: Unlike primitives, wrapper class objects can be null.
#Integer Wrapper Class
The Integer class wraps the primitive int.
#Constructor
Explore more resources
How are we doing?
Give us your feedback and let us know how we can improve