Uncaught TypeError: Cannot read property of undefined
When you run this code, you will get this message in browser:
In the above code, when you get undefined error , you need to make sure that whichever variables throws undefined error, is assigned a value to it.
In the above JacaScript you can the variable testVar is initialized the value of 99. So the script run successfully.
You can handle undefined by using if statement.
Also, undefined is of the type undefined:
Moreover, declare a variable then assign undefined to it: