Java Wrapper Classes Flashcards

Study Notes

Wrapper Classes Overview

Wrapper classes are found in the java.lang package and facilitate working with primitive types by providing constants and methods.

Integer Wrapper Class

The Integer class encapsulates the primitive type int, allowing it to be treated as an object.
Contains a single int field, enabling object-oriented functionalities.

Double Wrapper Class

The Double class encapsulates the primitive type double, allowing it to be treated as an object.
Contains a single double field, enabling object-oriented functionalities similar to the Integer class.

Class Constants

Constants are immutable values defined at the class level and can be accessed throughout the class without modification.

Integer Constants

Integer.MIN_VALUE: Represents the smallest integer value, which is -2^31.
Integer.MAX_VALUE: Represents the largest integer value, which is 2^31 - 1.

Integer Methods

intValue(): Method that retrieves the int value from an Integer object.

Underflow and Overflow

Underflow occurs when calculations produce a result that is too small for the available bit representation.
Overflow occurs when calculations result in a value too large for the bit representation, akin to a car's odometer exceeding its limit.

Autoboxing and Unboxing

Autoboxing refers to the automatic conversion process between primitive types and their corresponding wrapper class types.
Unboxing is the process of converting a wrapped object back into its corresponding primitive type.

Description

This quiz features flashcards focused on Java wrapper classes, specifically Integer and Double. You'll learn about the definitions and uses of these classes in the java.lang package, helping you understand how they relate to primitive types. Test your knowledge and improve your understanding of these important Java concepts.