I have a lot of folders and subfolders on my Sharepoint who's content type I want to change.
Is there a way I can change the content type of several folders at once ?
If you use SharePoint Online, chances are that you can use Flow. You can change the content type of an item with Flow with the action Update file properties. If the library allows management of content types, there will be a field where you can select the content type for the item.
You might also be able to do that with a SharePoint Designer 2013 workflow, but Flow is a lot easier to troubleshoot.
Edit: This kind of flow has not been prepared as a template and you will need to write it from scratch.
In Flow, click My Flows, then New > Create from blank and again Create from blank.
In the box "Search connectors and triggers" type manual. Now you should see the Flow button for mobile trigger. Click that to create a flow that can be manually started.
In the Flow designer, click New step, then click SharePoint and find the action Get files (properties onlY)
Specify the site and the library.
Then insert a new step, select SharePoint and find the action to Update file properties. Specify the same site and library as in the previous step and in the ID field use the Dynamic content picker to pick the ID from the Get files step. That will automatically insert the loop you need.
Now the Apply to each has been wrapped around the Update file properties. Continue configuring the Update file properties, which will now show the columns available to the document library.
Every action inside the loop will be applied to all documents returned by the Get files action.
When you have added all the actions, save the flow and then return to the My Flows page. Here you will see a triangle like a play button on a music player when you hover the mouse over the row with your flow. Click this to start the flow manually.
If you need more help with Flow, you may want to watch a few of the tutorials available with a brief search.
thank you @teylyn. Unfortunately I have been unsuccessful, even after reading and watching some tutorials.
and this is my documents library. it has these two folders and subfolders. The content type of all these folders should be changed
thank you very much.