Question

我是swift的新手。我需要从单词列表中获得一个前缀为#的字符串。这是我的字符串

“在6月14日的火灾之后，有30人被证实死亡，但预计总数会上升得更高。...一名男子在#Facebook上张贴了相信有人身体的照片从#Grenfell塔跳到他的死亡#fire已经#jiled了三个月“

我需要流动的单词列表：

["#Facebook","#Grenfell","#fire","#jailed"]

我花了很多时间但却无法弄清楚如何实现这一目标。

Answer 1

您可以这样做：

 let str = "Thirty people are confirmed dead after the June 14 fire, but the total is expected to rise far higher. ... A man who posted pictures on #Facebook of the body of someone believed to have leapt to his death from the #Grenfell Tower #fire has been #jailed for three months"

 let words = str.components(separatedBy: " ").filter { (element) -> Bool in
         return element.hasPrefix("#")
    }
 print(words)

Answer 2

这是一个简单的解决方案：

逻辑：将文本拆分为单词数组，然后使用谓词对其进行过滤。

    let stringText = "Thirty people are confirmed dead after the June 14 fire, but the total is expected to rise far higher. ... A man who posted pictures on #Facebook of the body of someone believed to have leapt to his death from the #Grenfell Tower #fire has been #jailed for three months"

    let wordsArray = stringText.characters.split{$0 == " "}.map(String.init)

    let filteredList = wordsArray.filter {NSPredicate(format:"SELF BEGINSWITH %@","#").evaluate(with: $0)}

Answer 3

使用NSRegularExpression过滤带有特定前缀的字符串 -

    //Xcode 8.3 swift 3.x
    var string: String = "Thirty people are confirmed dead after the June 14 fire, but the total is expected to rise far higher. ... A man who posted pictures on #Facebook of the body of someone believed to have leapt to his death from the #Grenfell Tower #fire has been #jailed for three months"

let regex = try? NSRegularExpression(pattern: "#(\\w+)", options: [])
let matches: [NSTextCheckingResult] = (regex?.matches(in: string, options: [], range: NSRange(location: 0, length: (string.characters.count ))))!
for match in matches {
    let wordRange = (match).rangeAt(1)
    let word = (string as NSString).substring(with: wordRange)
    print("Found tag - \(word)")
}




  // Objective c ->

 NSString*string = @"Thirty people are confirmed dead after the June 14 fire, but the total is expected to rise far higher. ... A man who posted pictures on #Facebook of the body of someone believed to have leapt to his death from the #Grenfell Tower #fire has been #jailed for three months";
    NSError *error = nil;

    NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"#(\\w+)" options:0 error:&error];
    NSArray *matches = [regex matchesInString:string options:0 range:NSMakeRange(0, string.length)];
    for (NSTextCheckingResult *match in matches) {
        NSRange wordRange = [match rangeAtIndex:1];
        NSString* word = [string substringWithRange:wordRange];
        NSLog(@"Found tag %@", word);
    }

从String中获取单词列表

3 个答案: