When checking for a null or empty variable, do you guys use xyz == "" && xyz == null OR xyz == "" || xyz == null OR something else ?

does that work in all cases?

if you're checking strings, yes. but don't forget that zero is falsey. If I know the variable's datatype (like, if I'm calling

record.getValue()

) then I'll explicitly check

if (xyz === '') {}

or

if (xyz !== '') {}

You can cast a truthy or falsey variable to a boolean using the double !!