# How to switch in different composer version in ubuntu To switch between different Composer versions on Ubuntu, particularly between major versions like Composer 1 and Composer 2, you can use the `self-update` command with specific flags.
**Switching between Composer 1 and Composer 2: **
To switch to Composer 1.
``` composer self-update --1 ```
To switch to Composer 2.
``` composer self-update --2 ```
Other useful `self-update` commands:
- **To update to the latest stable version (usually Composer 2):**
``` composer self-update ```
- **To revert to the previous Composer version:**
``` composer self-update --rollback ```
- **To preview a new Composer version before updating:**
``` composer self-update --preview ```
Important Notes:
- If you encounter permission errors when running `composer self-update`, you might need to run it with `sudo`, like `sudo composer self-update --2`. However, be cautious when using `sudo` with Composer, as it can sometimes lead to permission issues in your user's home directory. - Ensure your PHP environment is compatible with the Composer version you are switching to. Different Composer versions might have different PHP version requirements. - After switching versions, you can verify the current Composer version by running:
``` composer --version ```