用于字数计算的Swift字符串中的字数

let sentence = "I want to an algorithm that could help find out how many words are there in a string separated by space or comma or some character. And then append each word separated by a character to an array which could be added up later I'm making an average calculator so I want the total count of data and then add up all the words. By words I mean the numbers separated by a character,preferably space Thanks in advance"

let wordList =  sentence.components(separatedBy: .punctuationCharacters).joined().components(separatedBy: " ").filter{!$0.isEmpty}

print(wordList) // [I,want,to,an,algorithm,that,could,help,find,out,how,many,words,are,there,in,a,string,separated,by,space,or,comma,some,character,And,then,append,each,word,array,which,be,added,up,later,Im,making,average,calculator,so,I,the,total,count,of,data,and,add,all,By,mean,numbers,preferably,Thanks,advance]"
print(wordList.count)  // 79

extension String {
    var words: [String] {
        var words: [String] = []
        enumerateSubstrings(in: startIndex..<endIndex,options: .byWords) { word,_,_ in
            guard let word = word else { return }
            words.append(word)
        }
        return words
    }
}

print(sentence.words) // ["I","want","to","an","algorithm","that","could","help","find","out","how","many","words","are","there","in","a","string","separated","by","space","or","comma","some","character","And","then","append","each","word","array","which","be","added","up","later","I'm","making","average","calculator","so","I","the","total","count","of","data","and","add","all","By","mean","numbers","preferably","Thanks","advance"]

Swift 2.x

let sentence = "I want to an algorithm that could help find out how many words are there in a string separated by space or comma or some character. And then append each word separated by a character to an array which could be added up later I'm making an average calculator so I want the total count of data and then add up all the words. By words I mean the numbers separated by a character,preferably space Thanks in advance"

let wordList =  sentence.componentsSeparatedByCharactersInSet(NSCharacterSet.punctuationCharacterSet()).joinWithSeparator("").componentsSeparatedByString(" ").filter{$0 != ""}

print(wordList) // [I,advance]"
print(wordList.count)  // 79

问题是得到单词的计数,但是如果你需要这些单词,你可以使用这个扩展改编自Martin R在这个answer中建议的方法也能够处理撇号：

extension String {
    var words: [String] {
        var result:[String] = []
        enumerateSubstringsInRange(characters.indices,options: .ByWords) { result.append($0.substring!) }
        return result
    }
}