swift 字符串String的使用方法

1、声明

? 1 2 3 4 5 6 7 8 9 10 11 var str = "Hello, playground" //var str: String = "Hello, playground" // 空字符串 let emptyString = "" let emptyString2 = String() // 使用String()初始化字符串 let str2 = String("Hello, swift")

2、判断字符串是否为空

? 1 2 3 // 判断空字符串 str.isEmpty //false emptyString.isEmpty //true

3、字符串拼接

? 1 2 3 4 5 6 7 8 9 10 11 // String的粘合 let mark = "!!!" str + mark //Hello, playground!!! str //Hello, playground // 常量String和变量String str += mark str //Hello, playground!!! //str2 += mark //let 会报错

4、字符串插值

? 1 2 3 4 5 6 // 字符串插值 let name = "lxy" let age = 18 let height = 1.78 let s = "My name is \(name), I'm \(age) years old. I'm \(height) meters tall." print(s) //My name is lxy, I'm 18 years old. I'm 1.78 meters tall.

5、特殊字符

? 1 2 3 4 // 特殊字符 let s = "\\" =>\ let s = "\"" =>" let s = "\n" =>换行

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原文链接：http://blog.csdn.net/u012903898/article/details/52844130