How to check if function exists in javascript
Javascript might not be happy if you call function before it is being created. This can happen in a couple of cases.
You might be wondering how to check if function exists in javascript before calling it.
Lets say you have a onLoad logic, and there could be function definition below it. In that case, if you try to call the function from the onLoad, it might complain as
Uncaught referenceError: functionName is not defined
This happens only because the browser will be creating the function later and there is no precedence on this.
How to fix Uncaught referenceError: is not defined javascript error
In this case you can check if the function exists first and call it afterwards:
if (typeof functionName == 'function') {
functionName();
}
This will solve the problem. But there is a catch, you need to recall it again you make sure it is loaded.
Let me know if this solves your problem or not. I can add more based on your questions or suggestions.