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  • Swift

    下面对String常用的属性和方法做个总结

    1,判断是否为空:isEmpty
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    var str:String
    if str.isEmpty{
    }


    2,获取字符数量:countElements

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    let str = "hangge.com"
    println("(countElements(str))个字符")


    3,检查字符串是否有特定前缀/后缀:hasPrefix/hasSuffix

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    var str = "hangge.com"
    if str.hasSuffix(".com"){
    }


    4,还可以用“()”在字符串里包裹变量,常量

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    let name = "hangge.com"
    let msg = "欢迎来到 (name)"


    5,大小写转换:

    通过字符串的uppercaseString、lowercaseString、capitalizedString属性来访问一个字符串的大写/小写/首字母大写
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    let str = "Welecome to hangge.com"
             
    var uppercase = str.uppercaseString  //WELECOME TO HANGGE.COM
    var lowercase = str.lowercaseString  //welecome to hangge.com
    var capitalized = str.capitalizedString  //Welecome To Hangge.Com


    6,字符串截取

    (1)将String转化为NSString再截取
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    var str = "Welecome to hangge.com"
             
    var fromStr = (str as NSString).substringFromIndex(5) //ome to hangge.com
    var toStr = (str as NSString).substringToIndex(5)  //Welec
    var rangeStr =  (str as NSString).substringWithRange(NSMakeRange(4,1)) //c

    (2)直接调用String的对应方法(推荐)

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    var str = "Welecome to hangge.com"
                    
    let index = advance(str.startIndex, 5)
    let index2 = advance(str.endIndex, -5)
    var range = Range<String.Index>(start: index, end: index2)
     
    var fromStr = str.substringFromIndex(index)  //ome to hangge.com
    var toStr = str.substringToIndex(index2)  //Welecome to hangg
    var rangeStr = str.substringWithRange(range) //ome to hangg
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  • 原文地址:https://www.cnblogs.com/Free-Thinker/p/4841121.html
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