Using the special features of operators "||" and "&&" in JScript to achieve code simplification

In JScript, these logical operations are all about whether an expression is "meaningful"

For example, 0, "", null, false, undefined, NaN... etc. are all meaningless..

&& will return true or false
and a||b is, if a makes sense, it returns a, otherwise it returns b

So sometimes, I don't write code like this:
var obj=QuerySomeObject(); 
if(obj==null)return null; 
return ; 

I'll write it
return (QuerySomeObj()||{}).Property; 
Also, pay attention to the comparison between null and false.
0 ""  Equation and false  are equal when comparing ==.

But null is different. For example

if(!null) 
{ 
alert(1); 
} 
if(null==false) 
{ 
alert(2); 
} 
Tested in Firefox, the results are the same!