Ruby正则表达式怎样处理字符串

在Ruby中，使用正则表达式处理字符串非常常见。以下是一些关于如何在Ruby中使用正则表达式的例子：

1. 查找字符串中的匹配项：

str = "Hello, my name is Ruby." regex = /Ruby/ match = str.match(regex)  if match   puts "Found match: #{match[0]}" else   puts "No match found" end 

2. 查找字符串中所有匹配项：

str = "There are 3 Rubies and 5 Rubies in the basket." regex = /Ruby/gi matches = str.scan(regex)  puts "Found #{matches.size} matches:" puts matches.join(', ') 

3. 替换字符串中的匹配项：

str = "I like cats, cats are cute." regex = /cats/ replacement = "dogs" new_str = str.gsub(regex, replacement)  puts "Original string: #{str}" puts "New string: #{new_str}" 

4. 使用捕获组：

str = "The price of the item is $40." regex = /\$(\d+)/ matches = str.scan(regex)  if matches   puts "Found matches:"   matches.each do |match|     puts "Price: $#{match[0]}"   end else   puts "No match found" end 

这些例子展示了如何在Ruby中使用正则表达式处理字符串。你可以根据需要调整正则表达式和替换字符串来完成不同的任务。