I have noticed that (at least in React) there are different ways to call a function. I’d say:
onClick={myFunction}
onClick={myFunction()}
onClick={()=>myFunction}
onClick={()=>myFunction()} /*Not sure if I've seen this type*/
Being the case all are correct, what are the difference between them?
>Solution :
onClick={myFunction}
Assigns myFunction to onClick.
onClick={myFunction()}
Calls myFunction immediately and assigns the return value (which needs to be another function) to onClick.
This is often an error caused by people not understanding how () works and wanting the previous syntax.
onClick={()=>myFunction}
Creates a new function and assigns it to onClick.
The new function mentions myFunction but doesn’t do anything with it. It is a noop.
It is always a mistake.
onClick={()=>myFunction()}
Creates a new function, which calls myFunction, and assigns it to onClick.
This is usually a waste of resources. It is useful only if myFunction would do something with the event object that onClick passes to the event handler when called and you want to prevent that.
If you were to pass arguments to myFunction (which this example does not) then it would be more generally useful.