a1exlism/get_childNode's_index_in_parent.js

## get_childNode's_index_in_parent.js
//  core function
Function.call()
indexOf()

//  factory usage
let ul = document.querySelector('ul');
ul.addEventListener('click', function(event) {
  if(event.target.nodeName === 'LI') {
    alert(Array.prototype.indexOf.call(ul.childNodes, event.target));
  }
});
	// core function
	Function.call()
	indexOf()

	// factory usage
	let ul = document.querySelector('ul');
	ul.addEventListener('click', function(event) {
	if(event.target.nodeName === 'LI') {
	alert(Array.prototype.indexOf.call(ul.childNodes, event.target));
	}
	});