Why put in front of the file name “_” or “_” in scss/css?

Question

Why put _ in front of the filename in scss?

_filename.scss - Why does it need _ ?

Answer 1

When you include "_" in front of the file name, it won't be generated into CSS unless you import it into another sass files which is not partial.

suppose your folder structure is like this

/scss
 style.scss
 _list.scss
/css

if you run the command

sass --watch scss:css

only style.css and style.css.map files will be created, sass compiler will omit _list.scss without converting its content into a CSS file.

/scss
 style.scss
 _list.scss
/css
 style.css
 style.css.map

the only way that you can use partials is to import them into another .scss file with

@import 'list.scss';

if you remove the '_' in front of _list.scss the outcome of the command will be

/scss
 style.scss
 list.scss
/css
 style.css
 style.css.map
 list.css
 list.css.map

The main purpose of using partials is to break down our CSS code into several pieces which are easier to maintain. Hope this helps. Thanks.