I want to use global variable 'x' in the below hook funcion.
var x = 10; //global variable
var oldA = a;
a = function a(param){
alert(x); //showing error: x is undefined
return oldA(param);
}
How to resolve the error?
Your code works fine for me, but you might want to resolve x
to the global variable explicitly by using window.x
.
When not in a browser environment, or an environment where the global object isn't called window
, try:
(window || root || global || GLOBAL || this || self || {x: undefined).x
The {x:undefined}
object literal is just to make sure the expression doesn't throw up errors.
I've listed pretty much all names I know of that are given to the (strictly speaking nameless) global object, just use the ones that might apply to your case.
On the other hand, if the global variable x
might be reassigned by the time the function (a
) gets called, a closure would be preferable:
a = (function (globalX)
{
return function a(param)
{
console.log(globalX);
return oldA(param);
};
}(x || window.x));//pass reference to x, or window.x if x is undefined to the scope
Of course, if you're in strict mode, you need to be careful with implied globals, too.
That's all I can think of that is going wrong with your code, some more details might provide us with a clue of what's actually happening...
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With