Will lose your data if you delete an app?

Hi, i want to know if I restore my iPhone will i lose my apps? Is there anyway to get the content that was saved in the app back? I have no backups on my computer nor any backups online, everything was saved in my phone. Please guide me through!

Maybe

Backup your data in iCloud and when you restore your phone, use the backup and it will download all the apps but it won't save the data for every app. It only saves data for some apps.