DrRacket’s search and replace feature is interactive, similar to those in Safari, Firefox, and Emacs, but with a few differences.
To start a search, first select the Find menu item from the Edit menu. This will open a small editor at the bottom of the DrRacket window. Start typing in there and, as you type, all occurrences of the string you’re searching for will be circled in the editor window. Watch the space right next to the search window to see how many occurrences of the search string there are in your file. When you’re ready, you use the Find Again menu item to jump to the first occurrence of the search string. This will color in one of the circles. Use Find Again a second time to jump to the next occurrence.
If you click back into the definitions window, the Find Again menu item, DrRacket will move the selection to the next occurrence of the search string.
DrRacket also supports a mode where typing in the search editor takes you directly to the next occurrence of the search string, without selecting the Find Again menu item. In the preference dialog, in the Editing section and then in the General section is a checkbox labeled Search using anchors. When it is checked, DrRacket shows a little red dot and a red line indicating where the search anchor is. When the search anchor is enabled, typing in the search window jumps to the first occurrence of the search string after the anchor.