Swift documentation in Xcode is a useful tool for documenting code, making it easier for other developers to understand and use. By adding clear and concise documentation, we can improve the readability and usability of our code and make it easier for others to understand and use.

There are two methods to add documentation to our Swift code in Xcode: triple-slash (///) comments and block (/** */) comments.

Triple-slash Comment (///)

Triple-slash comments are typically used for concise, single-line documentation. They are displayed in the Quick Help panel in Xcode and are a quick way to add documentation for a specific piece of code.

Here is an example of triple-slash documentation for a function in Swift:

/// Returns the sum of two numbers.
///
/// - Parameters:
///   - a: The first number.
///   - b: The second number.
/// - Returns: The sum of `a` and `b`.
func add(a: Int, b: Int) -> Int {
    return a + b
}

Block Comment (/** */)

Block comments, denoted by /** */, are more suitable for longer, multi-line documentation. These comments are displayed as a standalone document in the documentation browser, allowing for more thorough explanations and examples.

Here is an example of block documentation for a class in Swift:

/**
 A class for representing a point in 2D space.

 This class has two properties, `x` and `y`, which represent the coordinates of the point. It also has a computed property, `distanceFromOrigin`, which calculates the distance of the point from the origin.
*/
class Point {
    var x: Double
    var y: Double

    /// The distance of the point from the origin.
    var distanceFromOrigin: Double {
        return sqrt(x * x + y * y)
    }

    init(x: Double, y: Double) {
        self.x = x
        self.y = y
    }
}

It's important to note that proper documentation is a key part of good coding practice, as it helps other developers understand the purpose and functionality of our code. Both triple-slash and block comments are useful tools for adding documentation to our Swift code in Xcode.

Last Words

In addition to describing the code itself, we can also use Swift documentation to include examples, notes, and other helpful information for users of our code. For example, we can include an example of how to use our function or class like this:

/// Returns the sum of two numbers.
///
/// - Parameters:
///   - a: The first number.
///   - b: The second number.
/// - Returns: The sum of `a` and `b`.
///
/// - Example:
///     let sum = add(a: 1, b: 2)
///     print(sum) // prints "3"
func add(a: Int, b: Int) -> Int {
    return a + b
}

we can also use special Markdown syntax to format our documentation in different ways. For example, we can use **bold** or *italic* text to emphasize certain words or phrases. We can also create lists using asterisks (*) or numbers like this:

/**
 A list of things to do:

 * Take out the trash
 * Water the plants
 * Feed the dog
 * Do the laundry
 */

In addition to these basic formatting options, we can also use Markdown to create tables, links, and other formatting elements. For a complete list of the Markdown syntax supported in Xcode documentation, you can refer to the "Formatting Your Documentation Content" documentation on the Apple Developer website.