Question on a typeof

[dmjpro]

[code=JAVASCRIPT]
if(typeof obj_name){}
if(typeof obj_name!=undef ined){}
[/code]

What is the difference between these two?
Basically undefined returns false ....if i want to check whether a object exists or not can't i do that simply using
[CODE=JAVASCRIPT]if(obj_ref){}[?CODE]
Could you explain ?

[Logician]

[code=JAVASCRIPT]
if(typeof obj_name){}[/code]

typeof returns the type as a string, so the above always evaluates true

if(typeof obj_name!=undefined){}

The above always evaluates true because undefined isn't a string.

if(typeof myObj != "undefined")
 .......

Also you can test by naming the object as a child; so if myObj is global

if( window.myObj != undefined )
 .......

[dmjpro]

typeof returns the type as a string, so the above always evaluates true
The above always evaluates true because undefined isn't a string.

if(typeof myObj != "undefined")
 .......

Also you can test by naming the object as a child; so if myObj is global

if( window.myObj != undefined )
 .......

Yeah Now I got it ....