//: Playground - noun: a place where people can play
import Foundation
var str = "Hello, playground"
str.capitalizedString // 字符串中所有单词首字母大写, 不改变str本身的值
str
str += ", hello, rinpe chan"
str.capitalizedString
str.uppercaseString // 全大写
str.lowercaseString // 全小写
// trim
var str2 = " hi ?!@"
str2.stringByTrimmingCharactersInSet(NSCharacterSet(charactersInString: " !?@")) // 切除字符串中的字符
// split
var str3 = "welcome to Shantou"
str3.componentsSeparatedByString(" ") // 分割
// 分割更复杂的字符串
var str4 = "rinpe, bobo! how-are-u?"
str4.componentsSeparatedByCharactersInSet(NSCharacterSet(charactersInString: " !-?"))
// join
var str5 = "-"
["1", "2", "3"].joinWithSeparator(str5)