Search and Replace

Working Code

Imagine this code is open in Vim:

const userName = "Alice";
const userAge = 25;
const userEmail = "alice@example.com";

function getUserName() {
  return userName;
}

function getUserAge() {
  return userAge;
}

Type /user and press Enter — the cursor jumps to the first occurrence of user in the file. Press n for the next result, N for the previous one.

Now type :%s/user/account/g and press Enter. Every user in the entire file becomes account.

Try It Yourself

Paste the code above into Vim and try:

1. Type /userName to find the first userName.
2. Press n repeatedly to cycle through every userName.
3. Press * to search for the word under the cursor instantly. n still cycles through results.
4. Type :%s/userName/accountName/gc to confirm each replacement one by one.
   • Press y to replace, n to skip.

"Why?"

Search

* is especially useful. Put the cursor on a variable name, press *, and you instantly see everywhere that variable appears.

Search highlights

Highlighting matches makes them easy to spot:

:set hlsearch       " turn on search highlighting
:nohlsearch         " turn off current highlight (short: :noh)
:set nohlsearch     " disable highlighting feature entirely

:noh only dismisses the current highlight temporarily. The next search highlights again. Add :set hlsearch to your config file to keep it always on.

Substitute

The basic substitute command looks like this:

:[range]s/pattern/replacement/[flags]

Range:

Flags:

Real-world examples

:s/foo/bar/          " replace first foo on current line with bar
:s/foo/bar/g         " replace every foo on current line with bar
:%s/foo/bar/g        " replace every foo in the file with bar
:%s/foo/bar/gc       " confirm each replacement in the whole file
:%s/foo/bar/gi       " case-insensitive substitute across the file
:5,20s/foo/bar/g     " substitute only on lines 5-20

Choices in confirm mode (c flag)

With gc, you choose what to do at each match:

Search combined with operators

You can use a search as a motion too:

d/function    → delete up to (but not including) "function"
c/end         → delete up to "end" and enter Insert mode

Deep Dive

/\d\+           " one or more digits
/\<word\>       " exactly "word" (no partial matches)
/^const         " lines starting with const
/;$             " lines ending with ;

function fetchData() {
  const data = fetch("/api/users");
  const dataList = data.json();
  console.log("data loaded:", dataList);
  return data;
}