How to set if else for vim's "set background = " for light and dark colorschemes?

Question

For themes like One or PaperColor, there are dark and light versions. For dark or light theme, I usually add my own customizations like bracket color, comment color... etc.

I tried to combine them so that everytime I set background=dark or light, with an if else statement. I tried the following but it doesn't work.

if (set background=dark)
    """ my own code here
endif

Please let me know how to go about this and thank you.

Answer 1

if &background ==# 'dark'
    " balabala
endif

&background get value of 'background' option, check :help let-&
==# compare strings case sensitively, check :help ==#