For debugging purposes I would like to display the value of different objects. Is there any way you can convert an object to a string to display all of its properties and values?
Not in a generic way. If you have an object that is set to a variable, like below:
Set(obj, { Name: "John Doe", Age: 33 })
Then you can use the & operator or the Concatenate function to create a string from that object:
Concatenate(
obj.Name,
" - ",
obj.Age
)
You can also see the value of the variables in the View -> Variables menu on the ribbon.
If you believe that this is a feature that should be supported, consider creating a new item in the PowerApps Ideas board.