（1）遍历
（2）长度
（3）拼接
（4）插值
（5）大小写
（6）trim
（7）split
……等等
- var a = "你好"
- var b = String()
-
- a.isEmpty
- b = "xxxxxyyyyy"
- b.isEmpty
-
- for c in b {
- println(c)
- }
-
- countElements(b)
-
- a += b
-
- var strss = "a: \(a), b: \(b)"
-
- let str_a = "abc"
- let str_b = "abc"
- str_a == str_b
-
- let str_c = "abd"
- str_b < str_c
-
- str_b.hasPrefix("a")
- str_b.hasSuffix("c")
-
- str_b.uppercaseString
- str_b.lowercaseString
-
- let str_d = "i am a good person"
- str_d.capitalizedString
-
-
- var s1 = " xx xx "
- s1.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceCharacterSet())
- s1.stringByTrimmingCharactersInSet(NSCharacterSet(charactersInString:" "))
-
-
- var s2 = "i am a good boy"
- s2.componentsSeparatedByString(" ")
- s2.componentsSeparatedByCharactersInSet(NSCharacterSet(charactersInString: "a "))
swift基础--字符串
原文：http://www.cnblogs.com/isItOk/p/4873161.html
