Regular expressions can be placed between the square brackets following the string. This line prints the first string which has three digits. puts "motherboard".gsub /board/, "land" With the gsub method we replace a 'board' string with a 'land' string. ...
正则表达式(regular expression)描述了一种字符串匹配的模式(pattern),可以用来检查一个串是否含有某种子串、将匹配的子串替换或者从某个串中取出符合某个条件的子串等。 正则表达式的组件可以是单个的字符、字符集合、字符范围、字符间的选择或者所有这些组件的任意组合。 正则表达式是由普通字符(例如字符 a 到 z)以及...
Regular expressions are amazing but sometimes they can be a bit tricky. Using a tool likerubular.comcan help you build yourruby regexin a more interactive way. Rubular also includes a Ruby regular expression cheat sheet that you will find very useful. Now it’s your turn to crack open that...
Anything can be done: testing a string for a match, extracting search matches, validating input, search-and-replace, splitting a string, etc. Using regular expressions with RubyLet RegexBuddy Make Regex Easy for YouDiscover how you can automate tedious tasks with regular expressions. Find out ...
string method "hello world".length#=>11"hello world".capitalize#=> Hello world"hello world".gsub("world","gril").upcase#=> HELLO GIRL 变量赋值 a ="hello"# => helloa.object_id# => 70353313681980a.replace("hello2")# => "hello2"a.object_id# => 70353313681980a ="hello"a.object_...
s["l"] = "L"; # Replace first occurrence of "l" with "L" end # Now we have "heLLo" Finally, you can index a string using a regular expression. (Regular expression objects are covered in §9.2.) The result is the first substring of the string that matches the ...
定义 正则表达式(Regular Expression) 用某种模式去匹配一类字符串的公式,主要用来描述字符串匹配的工具。 匹配 文本或字符存在不止一个部分满足给定的正则表达式,这是每一个这样的部分都被称为一个匹配。 匹配分为以下三种类型: 形容词性的匹配 即一个字符串匹配一个正则表达式 名词性的匹配 即在文本或字符串里匹...
- This is a modal window. No compatible source was found for this media. #!/usr/bin/rubytext="rails are rails, really good Ruby on Rails"# Change "rails" to "Rails" throughouttext.gsub!("rails","Rails")# Capitalize the word "Rails" throughouttext.gsub!(/\brails\b/,"Rails")puts...
result=eval("# we want to replace * with +") [reset]See the Solution Evaluating code read out of a file or a string coming from a database greatly increases the risk of execution of malicious code and is one of the reasons whyevalis considered evil.evalalso reduces the effectiveness of...
It is known that Regexp matching may take unexpectedly long. If your code attempts to match a possibly inefficient Regexp against an untrusted input, an attacker may exploit it for efficient Denial of Service (so-called Regular expression DoS, or ReDoS). ...