I'm trying to create a WordPress plug-in by myself, but are there any recommended sites, books, etc. for reference?
I tried to search the site myself, but I found only the main site for local creation.

I want to know mainly
・ There is explanation from basic part to registration method to official site
(I want to know the procedure for paid plug-ins)
・ I want to import jquery in the plug-in
How to prevent collision when already loaded by another plug-in

  • Answer # 1

    I have forgotten whether js has been imported, but the book "Bible of WordPress plugin development that dramatically increases the scalability of the site" is from the creation of a very simple plugin to the registration of the official directory It seemed to be listed.

  • Answer # 2

    See formula for registration

    To avoid conflicts with other plugins

    Through loading jQuery etc. using the built-in WP and using wp_enqueue_script

    The function name should have a plugin-specific prefix
    Create a separate namespace

    The constants, classes, and functions that are likely to collide
    Declare after checking existence