#pragma mark in Swift?

In Objective C, I can use #pragma mark to mark sections of my code in the symbol navigator. Since this is a C preprocessor command, it's not available in Swift. Is there a stand-in for this in Swift, or do I have to use ugly comments?


You can use // MARK:


Historical, Prior to Xcode 6 Beta 4

Just talked to an Engineer here at WWDC, and the current beta of Xcode doesn't implement the

// MARK:

style yet, but I'm told future versions will.

It was also suggested that making liberal use of class extensions might be a better practice anyway. Since extensions can implement protocols, you can eg put all of your table view delegate methods in an extension and group your code at a more semantic level than #pragma mark is capable of.


For those who are interested in using extensions vs pragma marks (as mentioned in the first comment), here is how to implement it from a Swift Engineer:

import UIKit

class SwiftTableViewController: UITableViewController {

    init(coder aDecoder: NSCoder!) {
        super.init(coder: aDecoder)

    }

    override func viewDidLoad() {
        super.viewDidLoad()

    }
}

extension SwiftTableViewController {
    override func numberOfSectionsInTableView(tableView: UITableView?) -> Int {
        return 1
    }

    override func tableView(tableView: UITableView?, numberOfRowsInSection section: Int) -> Int {
        return 5
    }

    override func tableView(tableView: UITableView?, cellForRowAtIndexPath indexPath: NSIndexPath?) -> UITableViewCell? {
        let cell = tableView?.dequeueReusableCellWithIdentifier("myCell", forIndexPath: indexPath) as UITableViewCell;

        cell.textLabel.text = "Hello World"

        return cell
    }

}

It's also not necessarily the best practice, but this is how you do it if you like.


Up to Xcode 5 the preprocessor directive #pragma mark existed.

From Xcode 6 on, you have to use // MARK:

These preprocessor features allow to bring some structure to the function drop down box of the source code editor.

some examples :

// MARK:

-> will be preceded by a horizontal divider

// MARK: your text goes here

-> puts 'your text goes here' in bold in the drop down list

// MARK: - your text goes here

-> puts 'your text goes here' in bold in the drop down list, preceded by a horizontal divider

update : added screenshot 'cause some people still seem to have issues with this :

在这里输入图像描述

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