Explain the concept of variables, constants, and data types in Swift.

In Swift, variables, constants, and data types are fundamental concepts used for storing and manipulating data within a program. Let's delve into each concept and understand how they work in Swift:

1. Variables: Variables in Swift are used to store and manage mutable data. They hold values that can change during the execution of a program. You can declare a variable using the `var` keyword, followed by the variable name and its optional type annotation. For example:

```
swift`var age: Int = 25`
```
In this example, `age` is a variable of type `Int` (integer) that holds the value `25`. You can modify the value of a variable at any point in your code using the assignment operator (`=`). For instance:

```
swift`age = 30`
```
Now, the `age` variable holds the value `30`. Variables provide flexibility when you need to store data that can change over time.

2. Constants: Constants, as the name suggests, hold values that remain constant or unchanging throughout the execution of a program. Once a constant is assigned a value, you cannot modify it. In Swift, you can declare constants using the `let` keyword, followed by the constant name and its optional type annotation. For example:

```
swift`let pi: Double = 3.14159`
```
In this case, `pi` is a constant of type `Double` that holds the value `3.14159`. It cannot be modified later in the code. Constants are useful when you want to ensure that a value remains unchanged and prevent accidental modifications.

3. Data Types: Swift is a statically typed language, which means that every variable and constant must have a specific data type. Data types determine the kind of values that can be stored in a variable or constant. Swift provides various built-in data types, including:

* Int: Represents whole numbers (both positive and negative) without fractional components.
* Double and Float: Represent floating-point numbers with decimal places. Double provides higher precision than Float.
* Bool: Represents Boolean values, `true` or `false`, for logical operations.
* String: Represents a sequence of characters.
* Array: Represents an ordered collection of elements of the same type.
* Dictionary: Represents a collection of key-value pairs.
* Tuple: Represents a group of values of different types.
* Optional: Represents a variable that may or may not hold a value.

For example, let's declare variables and constants of different data types:

```
swift`var score: Int = 100
let pi: Double = 3.14159
var isPassed: Bool = true
let greeting: String = "Hello, World!"
var numbers: [Int] = [1, 2, 3, 4, 5]
let userInfo: [String: Any] = ["name": "John", "age": 30, "isEmployed": true]
var person: (String, Int, Bool) = ("Alice", 25, true)
var temperature: Double? = 25.5`
```
In the above example, we declare variables and constants with their respective data types. Arrays, dictionaries, and tuples allow you to store multiple values of different types together.

Understanding variables, constants, and data types is crucial in Swift as they form the foundation for storing, manipulating, and organizing data within your code.