Swift 2：如何将动态数目的字符串分配给字符串数组？

Question

Context:

I'm attempting to create an app that populates a UICollectionView (tvOS) based on the contents of a folder in a local server I'm running. The way I'm trying to do this (and it may be completely wrong way) is to 'scrape' the html of my server pages.

I have the following property defined:

let moviesArray: [String] = ["<li>Example 1</li>", "<li>Example 2</li>"]

My UICollectionView will return the number of UICollectionViewCell's equal to moviesArray.count so I need this number (along with additional data that I won't speak to in this question).

Problem:

The number of files/folders I add to my server is dynamic and will increase / decrease depending on what movies I add to it or delete from it. This will obviously change the html which is returned.

I have the following piece of code that returns the html of my local server's URL and converts it to a string. I then create a substring of that based on a range, and then split out each individual <li> element from the html. Here's the code:

     do {

        let url:NSURL? = NSURL(string: "http://localhost:8888/Files/movies/")

        // 'contentsOfURL' returns the html code of the page
        let html:String? = try NSString(contentsOfURL: url!, encoding: NSUTF8StringEncoding) as String
        print(html)

        // creates a substring of 'html' based on a range defined below
        let ulString = html![(html?.startIndex.advancedBy(164))!...(html?.endIndex.advancedBy(-22))!]
        print("<ul> substring is: \(ulString)")

        // Splits each <li> into a separate string
        let liSplit = ulString.characters.split{$0 == "\n"}.map(String.init)
        print("li 1 is: \(liSplit[0])")
        print("li 2 is: \(liSplit[1])")
        print("li 3 is: \(liSplit[2])")

    } catch {
        print("the error is: \(error)")
    }

My Question:

How can I add or remove String objects to self.moviesArray based on the number of <li> elements that are in the html string which is returned? How will I assign each member of liSplit to self.moviesArray if it is a dynamic number?

Answer 1

You need to declare you moviesArray as variable, not as constant and initialize it:

var moviesArray = [String]()

Then you can go ahead and simply add all the retrieved element to it:

moviesArray += liSplit

Answer 2

There are two types of Array in Objective-C, 1) NSArray 2) NSMutableArray

You can't add objects to or remove objects from NSArray. You can add objects to or remove objects from NSMutableArray.

In swift, we have only one Array, ie Array eg Array<String> or [String], Array<NSURL> or [NSURL], etc

If you declare array with var keyword, it will be mutable version, so you can add or remove objects eg

var arrayString : Array<String> = Array()
arrayString.append("Hitendra")
arrayString.append("Solanki")

If you declare array with let keyword, it will not be mutable version, so you can't add or remove objects eg

var arrayString : Array<String> = Array()
arrayString.append("Hitendra")//not allowed
arrayString.append("Solanki")//not allowed

So just change the

let moviesArray: [String] = ["<li>Example 1</li>", "<li>Example 2</li>"]

to

var moviesArray: [String] = ["<li>Example 1</li>", "<li>Example 2</li>"]

and use following lines,

let liSplit = ulString.characters.split{$0 == "\n"}.map(String.init)

for listItem in liSplit {
moviesArray.append(listItem)
}