三 swift字符串和字符
//swift对字符串和字符的处理:字符串(String), Character(字符) //支持unicode let s1:String = "\u{24}";//美元符号 let s2 = "\u{2665}";//黑心图 var s3:String = "\u{1f496}";//红心图 println(s1); //字符串连接 var s4 = s1 + s2; s3 += s4; println(s3); //字符串插值 \(value) let m = 3; let msg = "这是字符串差值\(m)";//m被插入到msg中 //大小写转换 let s5 = "This is uppercaseString and lowercaseString"; println(s5.uppercaseString);//转换为大写 println(s5.lowercaseString);//转换为小些 println("\u{1f426}");