简单正则表达式的含义

Question

有人可以帮我解决这两个正则表达式：

First: "^\\s+|\\s+$"
Second: "\\s{2,}"

Answer 1

看看这个或用谷歌搜索。解释那些正则表达式并不复杂。

http://www.regular-expressions.info/reference.html#

例如：

\ s匹配空格 {2，}表示其中的2个或更多

Answer 2

为什么不使用工具dat可以“记录”表达式？这可以帮助您理解它们。

使用RegexBuddy（但在我看来是付费的最佳工具），表达式记录如下：

// ^\s+|\s+$
// 
// Options: ^ and $ match at line breaks
// 
// Match either the regular expression below (attempting the next alternative only if this one fails) «^\s+»
//    Assert position at the beginning of a line (at beginning of the string or after a line break character) «^»
//    Match a single character that is a “whitespace character” (spaces, tabs, and line breaks) «\s+»
//       Between one and unlimited times, as many times as possible, giving back as needed (greedy) «+»
// Or match regular expression number 2 below (the entire match attempt fails if this one fails to match) «\s+$»
//    Match a single character that is a “whitespace character” (spaces, tabs, and line breaks) «\s+»
//       Between one and unlimited times, as many times as possible, giving back as needed (greedy) «+»
//    Assert position at the end of a line (at the end of the string or before a line break character) «$»