[Go language] Learn Go--init () method from Docker source code and identifier first letter case

Init () method

If you want to do some initialization work in a go file, you can put the code in the Init () method.

The init () method is executed first.

// initializationof package}

Note: It is not an input parameter and a return parameter.

Identifier first letter case sensitivity

When identifier (e.g. Constant,variable,type,function,struct field, ...) The first letter of the name is capitalized, which means that the identifier is visible outside the package;

function similar to public.

Conversely, when the first letter of the identifier is lowercase, it means that the idenfitier is visible only within the package;

Similar to the role of private.

Note: Whether outside the package is visible and the go language reflection will have a certain relationship, if it is only visible within the package, there will be a problem in the reflection lookup.