废话不多说了，直接给大家贴代码了。

? 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 var string = "Hello-Swift" //获取某个下标后一个下标对应的字符 char="e" //swift2.2 //var char = string[startIndex.successor()] //swift3.0 var char = string[string.index(after: startIndex)] //获取某个下标前一个下标对应的字符 char2 = "t" //swift2.2 //var char2 = string[endIndex.predecessor()] //swift3.0 var char2 = string[string.index(before: string.endIndex)] //通过范围获取字符串中的一个子串 Hello //swift2.2 //var subString = string[startIndex...startIndex.advancedBy(4)] //swift3.0 var subString = string[startIndex...string.index(startIndex, offsetBy: 4)] //swift2.2 //var subString2 = string[endIndex.advancedBy(-5)...endIndex.predecessor()] //swift3.0 var subString2 = string[string.index(endIndex, offsetBy: -5)..<endIndex] //获取某个子串在父串中的范围 //swift2.2 //var range = string.rangeOfString("Hello") //swift3.0 var range = string.range(of: "Hello") //追加字符串操作 此时string = "Hello-Swift! Hello-World" //swift2.2 //string.appendContentsOf(" Hello-World") //swift3.0 string.append(" Hello-World") //在指定位置插入一个字符 此时string = "Hello-Swift!~ Hello-World" //swift2.2 //string.insert("~", atIndex: string.startIndex.advancedBy(12)) //swift3.0 string.insert("~", at: string.index(string.startIndex, offsetBy: 12)) //在指定位置插入一组字符 此时string = "Hello-Swift!~~~~ Hello-World" //swift2.2 //string.insertContentsOf(["~","~","~"], at: string.startIndex.advancedBy(12)) //swift3.0 string.insert(contentsOf: ["~","~","~"], at: string.index(string.startIndex, offsetBy: 12)) //在指定范围替换一个字符串 此时string = "Hi-Swift!~~~~ Hello-World" //swift2.2 //string.replaceRange(string.startIndex...string.startIndex.advancedBy(4), with: "Hi") //swift3.0 string.replaceSubrange(string.startIndex...string.index(string.startIndex, offsetBy: 4), with: "Hi") //在指定位置删除一个字符 此时string = "Hi-Swift!~~~~ Hello-Worl" //swift2.2 //string.removeAtIndex(string.endIndex.predecessor()) //swift3.0 string.remove(at: string.index(before:string.endIndex)) //删除指定范围的字符 此时string = "Swift!~~~~ Hello-Worl" //swift2.2 //string.removeRange(string.startIndex...string.startIndex.advancedBy(2)) //swift3.0 string.removeSubrange(string.startIndex...string.index(string.startIndex, offsetBy: 2)) var string2 = "My name is Jaki" //全部转换为大写 //swift2.2 //string2 = string2.uppercaseString //swift3.0 string2 = string2.uppercased() //全部转换为小写 //swift2.2 //string2 = string2.lowercaseString //swift3.0 string2 = string2.lowercased()

需要注意，在Swift3.0中Range结构体被划分成了两种类型，Range和ClosedRange，分别用来描述左闭右开区间和闭区间，对应到运算符为0..<10和0...10。

从上面的示例代码中可以看出，String类型中的很多方法命名进行了Swift风格的简化，改动较大的一个点是关于下标index的改变，移除了两个Index下标移动的方法，使用String类型的index()方法来进行下标的移动操作，编程更加安全。

以上所述是小编给大家介绍的初探Swift3.0带来的变化汇总，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对服务器之家网站的支持！

原文链接：http://blog.csdn.net/walkerwqp/article/details/53897018