if(something){
// Do this
}
Do this will happen, if “something” is equal to:
undefined
null
0 (as in the number)
“” (empty string)
NaN (not a number object)
Be careful! Any kind of object, or even the string “0” will evaluate to true!
The reason stuff like this works:
var myvar = me || you;
is because if “me” evaluates to true, that is what’s returned. Otherwise “you” will. That is assuming we don’t know if “me” or “you” are undefined at the moment.