Regarding icons usage in ionic 4

I am android developer and i am learning ionic4 , i have doubt about icons other then splash and app icons. in android app we if we need to display icon or image , first we need to generate different sizes of icons and we put in hdpi,ldpi and etc folders. and we will give path to ImageView(android) but in ionic how to give different sizes of drawable icon to ionic ,etc. and how will it take it respective image from drawable folder based device resolution.