作品链接：
http://www.jianshu.com/users/1e0f5e6f73f6/top_articles
let str = "Probably at least one of the constraints in the following list is one you don't want"
//.匹配除换行符以外的任意字符 *重复零次或更多次 +重复一次或更多次 ?重复零次或一次
do{
// 1.创建规则
let pattern1 = "[a-z]"
let pattern2 = "[A-Z]"
let pattern3 = "[\\s]"
//多个规则之间使用 | 符号连接
let pattern = pattern1 + "|" + pattern2 + "|" + pattern3
// 2.创建正则表达对象
let regex = try NSRegularExpression(pattern: pattern, options: NSRegularExpressionOptions.CaseInsensitive)
// 3.开始匹配
let res = regex.matchesInString(str, options: NSMatchingOptions(rawValue: 0), range: NSMakeRange(0, str.characters.count))
for checkingRes in res {
// 截取匹配的字符串
print((str as NSString).substringWithRange(checkingRes.range))
}
}catch{
print(error)
}
