The second icon in the activity bar is “Search”.

Clicking it shows the search interface:

You can click the icons in the Search input box to make the search case sensitive, or to match whole words (not substrings), and also use a regular expression for the search string.

To perform a search, type something and press enter.

Clicking the ▷ symbol on the left enables the “search and replace” tool.

Clicking the 3 dots shows a panel that lets you just include some specific kinds of files, and exclude other files:

Lessons in this unit: