Exporting your contacts on iOS
If you have your iPhone synced to iCloud then exporting your contacts to vCard format is easy.
1. Open iCloud and go to your contacts. Select one or more of them.
To select more than one contact, click the first contact, then click the last one while holding shift. To select more than one nonadjacent contacts, hold Ctrl and click each of the contacts you want to export.
2. Click the Action menu (the gear icon) and select Export vCard. Save the file to your computer.
Source: Apple Support