String Programming Guide

概述        String是一系列char数据的集合，如”hello, world”或”albatross”。它是苹果公司针对Swift语言编写的管理字符串的对象。String以优雅的方式结合了NSString和NSMutableString的优点，并简化了接口的使用。本文介绍了关于String日常开发过程中的一系列方法，供大家查阅。 类型别名 // MARK: 类型别名private fun

String是一系列char数据的集合，如”hello,world”或”albatross”。它是苹果公司针对Swift语言编写的管理字符串的对象。String以优雅的方式结合了Nsstring和NSMutableString的优点，并简化了接口的使用。本文介绍了关于String日常开发过程中的一系列方法，供大家查阅。

类型别名

// MARK: 类型别名private func testTypeAliases() {    let index = String.Index.self    print("\(index)")    let utf8index = String.UTF8Index.self    print("\(utf8index)")    let utf16index = String.UTF16Index.self    print("\(utf16index)")    let unicodeScalarIndex = String.UnicodeScalarIndex.self    print("\(unicodeScalarIndex)")    let greeting = "Guten Tag!"    greeting[greeting.startIndex] // G    greeting[greeting.endindex.predecessor()] // !    greeting[greeting.startIndex.successor()] // u    greeting[greeting.startIndex.advancedBy(7)] // a}

初始化

// MARK: 初始化private func testinitializers() {    // 空字符串    var string:String = String()    string = ""    // char初始化    let char: Character = "阳"    string = String(char)    string = String.init(char)    string = "\(char)"    // 通过CharacterVIEw    let charVIEw:String.CharacterVIEw = String.CharacterVIEw("阳君")    string = String(charVIEw);    // 通过UTF-16编码    let utf16:String.UTF16VIEw = string.utf16    string = String(utf16)    // 通过UTF-8编码    string = String(string.utf8)    // 多个字符串组合生成    string = String(stringInterpolation: "阳君","937447974")    // char初始化，连续count次    string = String(count: 3,repeatedValue: char)    // 通过其他常用数据初始化    string = String(stringInterpolationSegment: true)    string = String(stringInterpolationSegment: 24)    // 通过Nsstring初始化,不推荐    // 通过字符串生成字符串    string = Nsstring(string: "阳君") as String    string = Nsstring.init(string: "阳君") as String    // 组合生成    string = Nsstring(format: "%@","阳君") as String    print("\(string)")}

文件路径 *** 作

// MARK: - 文件路径 *** 作private func testWorkingWithPaths() {    var path = "IOS/Swift"    // 路径分割成数组    var pathComponents = (path as Nsstring).pathComponents    // 数组组合成路径    path = Nsstring.pathWithComponents(pathComponents)    // document目录    let documents:[String] = NSSearchPathForDirectorIEsInDomains(NSSearchPathDirectory.documentDirectory,NSSearchPathDomainMask.UserDomainMask,true)    let docDirPath = documents.first!    // 寻找文件夹下包含多少个路径    var complete = docDirPath.completePathIntoString(caseSensitive: true)    // 寻找文件夹下包含指定扩展名的文件路径    var outname = ""    let filterTypes = ["txt","pList"]    complete = docDirPath.completePathIntoString(&outname,caseSensitive: true,matchesIntoArray: &pathComponents,filterTypes: filterTypes)    print("completePathIntoString:\(complete)")    // 添加路径    path = (docDirPath as Nsstring).stringByAppendingPathComponent("test")    // 添加扩展    path = (path as Nsstring).stringByAppendingPathExtension("pList")!    print("是否绝对路径:\((path as Nsstring).absolutePath)")    print("最后一个路径名:\((path as Nsstring).lastPathComponent)")    print("扩展名:\((path as Nsstring).pathExtension)")    // 去掉扩展名    var tempPath:Any = (path as Nsstring).stringByDeletingPathExtension    // 去掉最后一个路径    tempPath = (path as Nsstring).stringByDeletingLastPathComponent    print("\(tempPath)")    // 转%格式码    let allowedCharacters:NSCharacterSet = NSCharacterSet.controlCharacterSet()    tempPath = path.stringByAddingPercentEnCodingWithAllowedCharacters(allowedCharacters)    // 转可见    tempPath = path.stringByRemovingPercentEnCoding}

文件读写 *** 作

// MARK: 文件读写 *** 作private func testfile() {    var string = "阳君；937447974"    // document目录    let documents:[String] = NSSearchPathForDirectorIEsInDomains(NSSearchPathDirectory.documentDirectory,true)    let docDirPath = documents.first!    let filePath = (docDirPath as Nsstring).stringByAppendingPathComponent("test.pList")    let fileUrl = NSURL(fileURLWithPath: filePath)    do {        // 写入        try string.writetofile(filePath,atomically: true,enCoding: NSUTF8StringEnCoding)        try string.writetoURL(fileUrl,enCoding: NSUTF8StringEnCoding)        // 读取        // 自动解析        try string = String(contentsOffile: filePath)        // 指定编码解析        try string = String(contentsOffile: filePath,enCoding: NSUTF8StringEnCoding)        // 使用默认的编码解析，如果不能解析，采取默认解析并返回解析编码        var enCoding:nsstringencoding = NSUTF16littleEndianStringEnCoding        try string = String(contentsOffile: filePath,usedEnCoding: &enCoding)        // URl 读取        try string = String(contentsOfURL: fileUrl)        try string = String(contentsOfURL: fileUrl,enCoding: NSUTF8StringEnCoding)        try string = String(contentsOfURL: fileUrl,usedEnCoding: &enCoding)    } catch {        print("错误:\(error)")    }}

获取字符串的Swift属性

// MARK: - 获取字符串的Swift属性private func testGettingPropertIEs() {    let string = String(stringInterpolation: "阳君","y;j","937447974")    // String.CharacterVIEw    print("String.CharacterVIEw:\(string.characters)")    // String.UnicodeScalarVIEw    print("String.UnicodeScalarVIEw:\(string.unicodeScalars)")    // String.UTF16VIEw    print("String.UTF16VIEw:\(string.utf16)")    // String.UTF8VIEw    print("String.UTF8VIEw:\(string.utf8)")    // hash值    print("hashValue:\(string.hashValue)")    // 是否为空    print("isEmpty:\(string.isEmpty)")}

获取字符串长度

// MARK: 获取字符串长度private func testGettingLength() {    let string = "阳君；937447974"    // 起始位置    var index =  string.startIndex    // 结束位置    index = string.endindex    print("\(index)")    // Nsstring方式获取长度    var length = (string as Nsstring).length    print("\(length)")    // 通过编码获取长度    length = string.lengthOfBytesUsingEnCoding(NSUTF8StringEnCoding)    // 返回存储时需要指定的长度    length = string.maximumLengthOfBytesUsingEnCoding(NSUTF8StringEnCoding)}

大小写变化

// MARK: - 大小写变化private func testChangingCase() {    let str = "阳君;y937447974J"    // 大写和小写    print("uppercaseString:\(str.uppercaseString);lowercaseString:\(str.lowercaseString)")}

得到数值

// MARK: 得到数值private func testGettingNumericValues() {    let string = "24"    let nStr = string as Nsstring // 借用Nsstring输出    print("doubleValue:\(nStr.doubleValue)")    print("floatValue:\(nStr.floatValue)")    print("intValue:\(nStr.intValue)")    print("integerValue:\(nStr.integerValue)")    print("longLongValue:\(nStr.longLongValue)")    print("boolValue:\(nStr.boolValue)")}

增加字符串

// MARK: - 增加字符串private func testCombiningStrings() {    var str = "阳君;937447974"    // 添加字符串    str.appendContentsOf(";Swift")    str += ";11"    str.write("222")    // string后增加字符串并生成一个新的字符串    str = str.stringByAppendingString(str)    // string后增加组合字符串并生成一个新的字符串    str = str.stringByAppendingFormat(";%@","OC")    // string后增加循环字符串，stringBypaddingTolength：完毕后截取的长度；startingAtIndex：从增加的字符串第几位开始循环增加。    str = str.stringBypaddingTolength(30,withString:";Swift",startingAtIndex:3)    // 指定位置插入Character    str.insert("5",atIndex: str.endindex.advancedBy(-1))    // 指定位置插入字符串    str.insertContentsOf("78".characters,at: str.startIndex.advancedBy(9))}

分割字符串

// MARK: 分割字符串private func testdivIDingStrings() {    let str = "阳君;937447974"    // 根据指定的字符串分割成数组    var array = str.componentsSeparatedByString(";")    // 通过系统自带的分割方式分割字符串    array = str.componentsSeparatedByCharactersInSet(NSCharacterSet.lowercaseLetterCharacterSet())    print("array\(array)")    // 指定位置后的字符串    var tempStr = str.substringFromIndex(str.startIndex.advancedBy(3))    // 指定位置前的字符串    tempStr = str.substringToIndex(str.startIndex.advancedBy(3))    // 指定范围的字符串    let range = str.endindex.advancedBy(-6)..<str.endindex    tempStr = str.substringWithRange(range)    print("tempStr:\(tempStr)")}

查找字符串

// MARK: 查找字符串private func testFindingStrings() {    let str = "阳君;\n937447974";    let searchRange = str.startIndex ..< str.startIndex.advancedBy(10)    // 根据NSCharacterSet查找    let cSet = NSCharacterSet.uppercaseLetterCharacterSet()    var range = str.rangeOfCharacterFromSet(cSet)    // 根据字符串查找    range = str.rangeOfString("93")    range = str.rangeOfString("93",options: NsstringCompareOptions.CaseInsensitiveSearch,range: searchRange,locale: nil)    print("\(range)")    // block 行查找    str.enumeratelines { (line,stop) -> () in        print("\(line)")        if "93" == line {            stop = true        }    }    // block查找，可设置查找方式，并得到找到的位置    str.enumerateSubstringsInRange(searchRange,options: NsstringEnumerationoptions.ByComposedCharacterSequences) { (substring,substringRange,enclosingRange,stop) -> () in        print("\(substring)")        if "9" == substring {            print("\(substringRange)")            stop = true        }    }}

替换字符串

// MARK: 替换字符串private func testReplacingSubstrings() {    var string = "阳君;937447974"    let replacingRange = string.startIndex ... string.startIndex.advancedBy(3)    // 全局替换    string = string.stringByReplacingOccurrencesOfString(";",withString: "+")    // 设置替换的模式，并设置范围    string = string.stringByReplacingOccurrencesOfString("+",withString: ";",options: NsstringCompareOptions.CaseInsensitiveSearch,range: replacingRange)    //将指定范围的字符串替换为指定的字符串    string.replaceRange(replacingRange,with: "12345")    string = string.stringByReplacingCharactersInRange(replacingRange,withString: "12345")}

删除字符串

// MARK: 删除字符串private func testRemovingSubstrings() {    var string = "阳君;937447974"    // 删除指定位置的字符串    string.removeAtIndex(string.startIndex.advancedBy(1))    // 根据范围删除字符串    let range = string.endindex.advancedBy(-6)..<string.endindex    string.removeRange(range)    // 删除所有    string.removeAll()    string.removeAll(keepCapacity: true)}

比较字符串

// MARK: 比较字符串private func testComparingStrings() {    var string = "阳君;937447974"    let compareStr = "阳君;837447974"    let searchRange = string.startIndex ..< string.endindex    // 前缀    var isHas = string.hasPrefix("阳君")    print("hasPrefix:\(isHas)")    // 后缀    isHas = string.hasSuffix("Swift")    print("hasSuffix:\(isHas)")    // 全比较是否相同    isHas = string == compareStr    // 比较大小    var result = string.compare(compareStr)    // 添加比较范围    result = string.compare(compareStr,range: searchRange,locale: nil)    print("result:\(result)")    // 返回两个字符串相同的前缀    string = string.commonPrefixWithString(compareStr,options: NsstringCompareOptions.CaseInsensitiveSearch)}

其他 参考资料

NSString Class Reference
NSMutableString Class Reference
The Swift Programming Language (Swift 2.1)
String Structure Reference

文档修改记录

时间	描述
2015-10-21	根据Swift2.1 String的API总结

版权所有：http://blog.csdn.net/y550918116j

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