Posting this here because it will hopefully help new developers. It explains it in the DM reference but its kind of unclear.
If you use the conditional OR operator, it will stop and return the value of the first true condition. This can be very useful at times

Example below
var/what = null

if(!what || !what.len)
world<<"youll never get an error doing this"
if(!what.len || !what)
world<<"if what does in fact not exist, youll get null.len error."
Not only does it stop, it returns the first true value.
var a = 2
var b = 0
var c = 3
src << (a || b) // 2
src << (c || a) // 3
That's what I (thought I said) meant to say.
Useful for other functions as well

var/a = 0
var/b = 2
var/c = 3
return (a || (b && c))

Returns a value of 3