JSFiddle - React, Tailwind, and code Playground

HTML

<button id="btn">Click me</button>

JavaScript

function myHandler (event) {
	console.log('Event handler:', event.data.array);
}

var arr = [];

setTimeout(function() {
  // arr = [1, 2, 3]; // This doesn't work
  
  // This works
  arr.push(1);
  arr.push(2);
  arr.push(3);
}, 0);

$("#btn").on("click", {array:arr}, myHandler);