Swift字符串操作(截取、替换)String

字符串String仿照NSString操作，swift中String使用的start，len，end，等是Index类型，不是Int类型，所以有两种方法可以解决

1、使用String方法，使用Index类型

2、强转为NSString类型

//字符串replace方法

public
func kStringByReplaceString(string:String,replaceStr:String,willReplaceStr:String) ->String{

return string.stringByReplacingOccurrencesOfString(replaceStr, withString: willReplaceStr)

//
使用NSString方法

// return (string as NSString).stringByReplacingOccurrencesOfString(replaceStr, withString: willReplaceStr)

}

//字符串replace方法

public
func kStringByReplaceInRange(var string:String,replaceString:String,start:Int,len:Int)
-> String{

let startindex = string.startIndex.advancedBy(start)

let endindex = string.endIndex.advancedBy(start + len - string.characters.count)

string.replaceRange(Range(start: startindex, end: endindex), with: replaceString)

return string

//使用NSString方法

// return (string as NSString).stringByReplacingCharactersInRange(NSMakeRange(start, len), withString: replaceString)

}

//字符串subStringToIndex

public
func kSubStringToIndex(string:String, to:Int) ->String {

//获取截取的Index

let toindex = string.startIndex.advancedBy(to)

let subString = string.substringToIndex(toindex)

return subString

// return (string as NSString).substringToIndex(to)

}

//字符串subStringFromIndex

public
func kSubStringFromIndex(string:String, from:Int) ->String {

//获取截取的Index

//let fromindex = string.endIndex.advancedBy(from - string.characters.count)

let fromindex = string.startIndex.advancedBy(from)

let subString = string.substringFromIndex(fromindex)

return subString

}

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