[regex] Visual Studio Code Search and Replace with Regular Expressions

I want to use "Search And Replace" in Visual Studio Code to change every instance of <h1>content</h1> to #### content within a document using a Regular Expression.

How can I accomplish that?

If you want ex. change all country codes in .json file from uppercase to lowercase:

ctrl+h
alt+r
alt+c

Find: ([A-Z]{2,})
Replace: $1

alt+enter
F1
type: lower -> select toLoweCase
ctrl+alt+enter

ex file:

[
 {"id": "PL", "name": "Poland"},
 {"id": "NZ", "name": "New Zealand"},
 ...
]

Make sure Match Case is selected with Use Regular Expression so this matches. [A-Z]* If match case is not selected, this matches all letters.

For beginners, I wanted to add to the accepted answer, because a couple of subtleties were unclear to me:

To find and modify text (not completely replace),

1. In the "Find" step, you can use regex with "capturing groups," e.g. your search could be la la la (group1) blah blah (group2), using parentheses.

2. And then in the "Replace" step, you can refer to the capturing groups via $1, $2 etc.

So, for example, in this case we could find the relevant text with just <h1>.+?<\/h1> (no parentheses), but putting in the parentheses <h1>(.+?)<\/h1> allows us to refer to the sub-match in between them as $1 in the replace step. Cool!

Notes

• To turn on Regex in the Find Widget, click the .* icon, or press Cmd/Ctrl Alt R

• $0 refers to the whole match

• Finally, the original question states that the replace should happen "within a document," so you can use the "Find Widget" (Cmd or Ctrl + F), which is local to the open document, instead of "Search", which opens a bigger UI and looks across all files in the project.