Creating an unused variable, why?

Question

go

https://github.com/gin-gonic/gin/blob/master/route...
In modules to call init, what's the point of this case?

Answer 1

Initializations (not this case),
Remains from debugging,
Type checks (we force the compiler to check everything for us).
In this case, the third one.
var _ IRouter = &RouterGroup{}
Verify that the RouterGroup structure implements the IRouter interface.
This is part of the code to test.
True, this is not a separate active test, those that are written in *_test.go files.
But we force additional checks to be carried out at the compilation stage.

Answer 2

Probably so that the static analyzer does not swear that the types are declared and not used.

Answer 3

For example jsfiddle.net/ayL7b1tv

Answer 4

Under the day and month, allocate a separate block of fixed width with text alignment to the right for the number and to the left for the month.