Pass a JavaScript function as parameter

Question

How do I pass a function as a parameter without the function executing in the \"parent\" function or using eval()? (Since I\'ve read that it\'s insecure.)

Answer 1

Some time when you need to deal with event handler so need to pass event too as an argument , most of the modern library like react, angular might need this.

I need to override OnSubmit function(function from third party library) with some custom validation on reactjs and I passed the function and event both like below

ORIGINALLY

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MADE A NEW FUNCTION upload and called passed onSubmit and event as arguments

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upload(event,fn){
  //custom codes are done here
  fn(event);
}