blocks|key|2656107|text|您需要将数组还原为字符串：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2656108|var+output+=+reduce(array,+"")+{+(existing,+toAppend)+in
++++if+existing.isEmpty+{
++++++++return+toAppend
++++}
++++else+{
++++++++return+"\(existing)\n\(toAppend)"
++++}
}
output.writeToFile(...)|code-block|syntax|javascript|2656109|reduce方法接受一个集合并将其合并到一个实例中。它需要一个初始实例和闭包来将集合的所有元素合并到原始实例中。|offset|length|style|CODE|2656110|我的示例以一个空字符串作为它的初始实例。然后，闭包检查现有输出是否为空。如果是的话，它只需要返回要追加的文本，否则，它将使用串内插返回现有的输出和中间带有换行符的新元素。|2656111|使用Swift的各种语法糖特性，可以将整个还原简化为：|2656112|var+output+=+reduce(array,+"")+{+$0.isEmpty+?+$1+:+"\($0)\n\($1)"+}|2656113|entityMap|0|LINK|mutability|MUTABLE|url|https://developer.apple.com/library/prerelease/ios/documentation/Swift/Conceptual/Swift_Programming_Language/StringsAndCharacters.html#//apple_ref/doc/uid/TP40014097-CH7-XID_420^0|0|0|0|6|0|1Q|3|0|0|0|0^^$0|@$1|2|3|4|5|6|7|10|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|11|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|12|8|@$I|13|J|14|K|L]]|9|@]|A|$]]|$1|M|3|N|5|6|7|15|8|@]|9|@$I|16|J|17|1|18]]|A|$]]|$1|O|3|P|5|6|7|19|8|@]|9|@]|A|$]]|$1|Q|3|R|5|D|7|1A|8|@]|9|@]|A|$E|F]]|$1|S|3|-4|5|6|7|1B|8|@]|9|@]|A|$]]]|T|$U|$5|V|W|X|A|$Y|Z]]]]

You need to reduce your array back down to a string:

<pre><code>var output = reduce(array, "") { (existing, toAppend) in
 if existing.isEmpty {
 return toAppend
 }
 else {
 return "\(existing)\n\(toAppend)"
 }
}
output.writeToFile(...)
</code></pre>

The <code>reduce</code> method takes a collection and merges it all into a single instance. It takes an initial instance and closure to merge all elements of the collection into that original instance.

My example takes an empty string as its initial instance. The closure then checks if the existing output is empty. If it is, it only has to return the text to append, otherwise, it uses <a href="https://developer.apple.com/library/prerelease/ios/documentation/Swift/Conceptual/Swift_Programming_Language/StringsAndCharacters.html#//apple_ref/doc/uid/TP40014097-CH7-XID_420" rel="nofollow">String Interpolation</a> to return the existing output and the new element with a newline in between.

Using various syntactic sugar features from Swift, the whole reduction can be reduced to:

<pre><code>var output = reduce(array, "") { $0.isEmpty ? $1 : "\($0)\n\($1)" }
</code></pre>

blocks|key|361592|text|Swift提供了许多遍历数组的方法。您可以循环遍历字符串并逐个打印到文本文件。差不多是这样的：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|361593|for+theString+in+myArray+{
++++theString.writeToFile(myPath,+atomically:+false,+encoding:+NSUTF8StringEncoding,+error:+nil);
}|code-block|syntax|javascript|361594|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Swift offers numerous ways to loop through an array. You can loop through the strings and print to a text file one by one. Something like so:

<pre><code>for theString in myArray {
 theString.writeToFile(myPath, atomically: false, encoding: NSUTF8StringEncoding, error: nil);
}
</code></pre>

blocks|key|2656190|text|正如drewag在接受的帖子中指出的那样，您可以从数组构建一个字符串，然后在字符串上使用writeToFile方法。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2656191|但是，您可以简单地使用Swift的Array.joinWithSeparator来使用更少的代码和更好的性能来完成同样的任务。|2656192|例如：|2656193|//+swift+2.0
let+array+=+[+"hello",+"goodbye"+]
let+joined+=+array.joinWithSeparator("\n")
do+{
++++try+joined.writeToFile(saveToPath,+atomically:+true,+encoding:+NSUTF8StringEncoding)
}+catch+{
++++//+handle+error
}

//+swift+1.x
let+array+=+[+"hello",+"goodbye"+]
let+joined+=+"\n".join(array)
joined.writeToFile(...)|code-block|syntax|javascript|2656194|entityMap^0|18|B|0|H|N|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|T|8|@$9|U|A|V|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|W|8|@]|D|@]|E|$]]|$1|J|3|K|5|L|7|X|8|@]|D|@]|E|$M|N]]|$1|O|3|-4|5|6|7|Y|8|@]|D|@]|E|$]]]|P|$]]

As drewag points out in the accepted post, you can build a string from the array and then use the <code>writeToFile</code> method on the string.

However, you can simply use Swift's <code>Array.joinWithSeparator</code> to accomplish the same with less code and likely better performance.

For example:

<pre><code>// swift 2.0
let array = [ "hello", "goodbye" ]
let joined = array.joinWithSeparator("\n")
do {
 try joined.writeToFile(saveToPath, atomically: true, encoding: NSUTF8StringEncoding)
} catch {
 // handle error
}

// swift 1.x
let array = [ "hello", "goodbye" ]
let joined = "\n".join(array)
joined.writeToFile(...)
</code></pre>

blocks|key|360447|text|使用Swift+5，我猜使用Swift+4，您可以使用代码片段，这对我来说很好。|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|360448|let+array+=+["hello",+"world"]
let+joinedStrings+=+array.joined(separator:+"\n")

do+{
++++try+joinedStrings.write(toFile:+outputURL.path,+atomically:+true,+encoding:+.utf8)
}+catch+let+error+{
++++//+handle+error
++++print("Error+on+writing+strings+to+file:+\(error)")
}|code-block|syntax|javascript|360449|entityMap^0|2|7|E|7|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]|$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|R|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|S|8|@]|D|@]|E|$]]]|L|$]]

With Swift 5 and I guess with Swift 4 you can use code snippet which works fine to me.

<pre><code>let array = ["hello", "world"]
let joinedStrings = array.joined(separator: "\n")

do {
 try joinedStrings.write(toFile: outputURL.path, atomically: true, encoding: .utf8)
} catch let error {
 // handle error
 print("Error on writing strings to file: \(error)")
}
</code></pre>

I read into myArray (native Swift) from a file containing a few thousand lines of plain text..

<pre><code>myData = String.stringWithContentsOfFile(myPath, encoding: NSUTF8StringEncoding, error: nil)
var myArray = myData.componentsSeparatedByString("\n")
</code></pre>

I change some of the text in myArray (no point pasting any of this code).

Now I want to write the updated contents of myArray to a new file.
I've tried this ..

<pre><code>let myArray2 = myArray as NSArray
myArray2.writeToFile(myPath, atomically: false)
</code></pre>

but the file content is then in the plist format.

Is there any way to write an array of text strings to a file (or loop through an array and append each array item to a file) in Swift (or bridged Swift)?

Swift - Write an Array to a Text File

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我从一个包含几千行纯文本的文件中读取myArray (本机Swift)。myData = String.stringWithContentsOfFile(myPath, encoding: NSUTF8StringEncoding, error: nil)var myArray = myData.componentsS...

问快速地将数组写入文本文件
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