Update, i just find the solution if anyone is having the same problem i have to add the following lines to user setting json
"editor.defaultFormatter": "esbenp.prettier-vscode",
"[javascript]": {
"editor.defaultFormatter": "esbenp.prettier-vscode"
}
Answer from Diegohp141 on Stack OverflowVideos
Update, i just find the solution if anyone is having the same problem i have to add the following lines to user setting json
"editor.defaultFormatter": "esbenp.prettier-vscode",
"[javascript]": {
"editor.defaultFormatter": "esbenp.prettier-vscode"
}
Press Ctrl+shift+p and type Preferences: Open User Settings (JSON). In that json file add the following line and save. This should enable so vscode formats the code each time you save.
{
"editor.formatOnSave": true
}
- Select
File -> Preferences -> Settings(Ctrl+comma) and search formformatter - Set Prettiers as Default formatter.

If above does not work:
ctrl+shift+p > Format Document With... > Configure Default Formatter... > Prettier - Code formatter
This also work with ctrl+shift+I
If doing what @Simin Maleki mentioned does not solve it for you, there is a chance that your default formatter is not set:
File > Preferences > Settings > Search for "default formatter"
Make sure your Editor: Default Formatter field is not null but rather Prettier - Code formatter (esbenp.prettier-vscode) and that all the languages below are ticked. This fixed my issue.
STEP BY STEP WALKTHROUGH

Also make sure that your format on save is enabled:

I'm more of the "edit the JSON" type of user of VSCode, and the answer from Masud was confusing to me because of that. It did push me in the right direction and I want to share for other like myself, more familiar with the .vscode/settings.json(s) than with that graphical Settings Editor.
settings.json edits - add these:
{
"editor.defaultFormatter": "esbenp.prettier-vscode",
"editor.formatOnSave": true
}
.prettierrc edit or add a file by that name at the root of your project for any custom settings. Here are some of my favs:
{
"singleQuote": true,
"tabWidth": 2,
"trailingComma": "none"
}
Then, you can sanity check against those rules. I just added a trailing comma in an object block (in a Styles block in the sample Expo tsx component, in my case - brand new project) and see it removed on save... Then, remove the trailingComma rule, save, and try the comma again and see that the comma stays.
Regarding Auto Code Formatting:
For anyone starting out with VSCode - Expo, React-Native devs or having some issues with code formatting, please find below the simplest solution I could find (ESLint is a bit confusing / complex unless you are fairly familiar) - link to Expo guide is here if you would really like to do this (https://docs.expo.dev/guides/using-eslint/) - It is a bit complicated if you are just starting out and I find ESLint to cause too much bloat messaging on my code editor screen, especially now that there are things such as copilot etc.
[Instructions] Simply set up Prettier (no ESLint):
- Add 'Prettier - Code Formatter' extension in VSCode and enable it
- Go to the VSCode settings to set both the User and Workspace fields for a) Editor: Default Formatter to "Prettier - Code formatter", then b) check to enable Format on Save (I also checked Notebook > Format on Save).
Now get to Coding!!!
Some Next Steps:
You can check out the Expo Guide (or similar) for further best practices but it will take some time to get it all setup.
Prettier should already auto-format on save and you can further configure it by adding a .prettierrc file at the root of your project and following https://github.com/expo/expo/tree/main/packages/eslint-config-universe#customizing-prettier which should override the default settings you have set up for all your projects.
You can later setup linting as well which is generally more useful down the line for when working with remote/shared repositories (ie: they contain explanations for the correction, etc.). Causes a bit of bloat but it's quite helpful for navigating a new team / codebase (ex Amazon SDE) to understand the style guidelines being used, fixing an entire project programmatically via a script etc. with ESLint.
Follow these steps:
- CTRL + SHIFT + P
- Format Document (in pop-up bar)
- Select
Format Document - Select
Configure Default Formatter... - Select
Prettier - Code formatter
Done!
In VSCode settings, search for "Editor: Default Formatter", set it to esbenp.prettier-vscode and restart VSCode.