Why is the data type of the variable not specified?
In this example, you used that variable in the output parameter and before that it was initialized to zero. But I do not understand the data type of the variable before it was used to store the output of the stored procedure.
Thanks for reaching out.
The important thing is that the output parameter is INT, so you need to provide such data type. This is why we initialize the variable with 0, which is INT and provide it as an output parameter to the procedure.
Hope this helps.