> For the complete documentation index, see [llms.txt](https://fashaun.gitbook.io/dev-vim/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://fashaun.gitbook.io/dev-vim/variables.md).

# Variables

View Vimscript not a single command but as a programming language.

```
:let foo = "bar"
:echo foo
```

foo output: bar

```
:let foo = 42
:echo foo
```

foo output: 42

## Options as Variables

Using an & in front of a variable tells Vim that you're referring to the option, not a variable that happens to have the same name.

Normal variable

```
:set textwidth=80
:echo &textwidth
```

textwidth output: 80

Boolean variable (true:1,false:0)

```
:set nowrap
:echo &wrap
```

wrap output: 0

```
:set wrap
:echo &wrap
```

wrap output: 1

```
:let &textwidth = 100
:set textwidth?
```

textwidth output: 100

```
:let &textwidth = &textwidth + 10
:set textwidth?
```

textwidth output: 110

## Local Options

If you want to set the local value of an option as a variable, instead of the global value, you need to prefix the variable name.

Open two files in separate splits. Run the following command:

`:let &l:number = 1`

Now switch to the other file and run this command:

`:let &l:number = 0`

## Registers as Variables

You can also read and set registers as variables.

`:let @a = "hello!"`

Now put your cursor somewhere in your text and type

```
"ap
```

This command tells Vim to "paste the contents of register a here". We just set the contents of that register, so Vim pastes hello! into your text.

Registers can also be read. Run the following command:

`:echo @a`

Vim will echo hello!.

Select a word in your file and yank it with y, then run this command:

`:echo @"`

Vim will echo the word you just yanked. The " register is the "unnamed" register, which is where text you yank without specifying a destination will go.

Perform a search in your file with /$your\_word

```
/$your_word
:echo @/
```

Vim will echo the search pattern you just used. This lets you programmatically read and modify the current search pattern, which can be very useful at times.

## Exercises (not finish)

Go through your \~/.vimrc file and change some of the set and setlocal commands to their let forms. Remember that boolean options still need to be set to something.

Try setting a boolean option like wrap to something other than zero or one. What happens when you set it to a different number? What happens if you set it to a string?

Go back through your \~/.vimrc file and undo the changes. You should never use let if set will suffice -- it's harder to read.

Read :help registers and look over the list of registers you can read and write.

## Variable Scoping

When we used b: in the variable name we told Vim that the variable hello should be local to the current buffer b.

Vim has many different scopes for variables, but we need to learn a little more about Vimscript before we can take advantage of the rest. For now, just remember that when you see a variable that start with a character and a colon that it's describing a scoped variable.