React onClick - pass event with parameter

Question

Without Parameter

function clickMe(e){
  //e is the event
}

With Para

Answer 1

Currying with ES6 example:

const clickHandler = param => event => {
  console.log(param); // your parameter
  console.log(event.type); // event type, e.g.: click, etc.
};

Our button, that toggles handler:

 clickHandler(1)(e)}>Click me!

If you want to call this function expression without an event object, then you'd call it this way:

clickHandler(1)();

Also, since react uses synthetic events (a wrapper for native events), there's an event pooling thing, which means, if you want to use your event object asynchronously, then you'd have to use event.persist():

const clickHandler = param => event => {
  event.persist();
  console.log(event.target);
  setTimeout(() => console.log(event.target), 1000); // won't be null, otherwise if you haven't used event.persist() it would be null.
};

Here's live example: https://codesandbox.io/s/compassionate-joliot-4eblc?fontsize=14&hidenavigation=1&theme=dark