I am trying to catch a series of tags with regex:

/<shi>(\n|<shi\n>/

How do I match the cases below:

• <shi>
• <\nshi>
• <\nshi\n>
• <shi\n\n>
  ... (And more cases like that)

CodePudding user response：

/<\n*shi\n*>/ should do the job. Let's see why:

• < will match the character < once
• \n* will match the newline character between 0 and unlimited times (greedy)
• shi will match the characters shi literally (case sensitive)
• \n* will match the newline character between 0 and unlimited times (greedy)
• > will match the character > once

@NNL993's answer (<(\n )?shi(\n )?>) also works, but it uses capturing groups.

• \n will match the newline character
• will match the previous token (newline character) between one and unlimited times (greedy)
• ? will match the previous token ((\n ) group) between zero and one time