NSNumber is a fundamental class in the Apple environment that allows developers to work with numerical values in an object-oriented manner. It provides a way to encapsulate primitive data types such as integers, floats, and doubles into objects. This is important because it allows for easier manipulation and passing of numerical values between different parts of an application.

In the Apple environment, NSNumber is commonly used in various scenarios such as storing numerical data in collections like arrays and dictionaries, as well as in user interface elements like labels and text fields. It provides a convenient way to convert between different numerical types and perform arithmetic operations.

To align with the Apple environment, NSNumber supports the Objective-C and Swift programming languages. The examples provided in this article will be in Swift, which is the recommended language for developing applications on Apple platforms.

Examples:

1. Creating an NSNumber object with an integer value:

let intValue = 42
let number = NSNumber(value: intValue)

2. Creating an NSNumber object with a floating-point value:

let floatValue = 3.14
let number = NSNumber(value: floatValue)

3. Converting an NSNumber object to an integer:

let number = NSNumber(value: 42)
let intValue = number.intValue

4. Converting an NSNumber object to a floating-point value:

let number = NSNumber(value: 3.14)
let floatValue = number.floatValue

5. Performing arithmetic operations with NSNumber objects:

let number1 = NSNumber(value: 10)
let number2 = NSNumber(value: 5)
let sum = number1.intValue + number2.intValue
let product = number1.intValue * number2.intValue