The <output> block allows you to define an output for a “user” block.
•« out_0 » : This is the variable that will be output from the “user” block currently being edited. There is no default value, but a default value can be added to each instance of a <output> block. This input can be renamed; the new name will appear in the external interface of the user block currently being edited as an output.
•There is no output
The input type can be any type.
The block named “rule of 3” contains three “input” blocks and one “output” block.
Since the block named “block1” references the “rule of 3” block, the external interface of the “rule of 3” block is displayed there with its three inputs and one output.