Tek-Tips is the largest IT community on the Internet today!
Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!
-
Congratulations gkittelson on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!
how do i check if variable exists
- Thread starter tomy
- Start date
AndrewGrabovsky
Programmer
Hi tomy! Use this:
alert(window.var_name);
where var_name is your variable name.
If it already exists, you'll get it's value.
If not, you'll see "undefined" in opened message box.
Andrew | starway@mail.com
alert(window.var_name);
where var_name is your variable name.
If it already exists, you'll get it's value.
If not, you'll see "undefined" in opened message box.
Andrew | starway@mail.com
luciddream
Programmer
you can use this:
if(varname)
{
//exists
}
or you can use:
if(typeOf(varname) != "undefined"
adam@aauser.com
if(varname)
{
//exists
}
or you can use:
if(typeOf(varname) != "undefined"
adam@aauser.com- Status
Similar threads
- Locked
- Question