i'm find the oldest file in sub-deep folders in my PC and i'm interested it, self made jQuery Clone; wow!!

fake-clone-jquery.js

"use strict";

class fn
{
	constructor(selector){
		this.selector = this.select(selector);
	}

	// select
	select(selector) {
		if(typeof selector === 'string') return this.strSelector(selector.toString().trim());
		else if(selector !== null && typeof selector === 'object') return this.objSelector(selector);
		else return null;
	}

	// str Selector
	strSelector(selectorText) {
		if(selectorText.startsWith('.')) return this.selectClass(selectorText.substr(1));
		else if(selectorText.startsWith('#')) return this.selectId(selectorText.substr(1));
		else if(/^(_|[a-z]){1,}(_|-|[a-z0-9]){0,}$/i.test(selectorText)) return this.selectElm(selectorText);
		else return null;
	}

	selectClass(classText) {
		this.selector = document.getElementsByClassName(classText).forEach(e => e);
	}
	selectId(idText) {
		return document.getElementById(idText);
	}
	selectElm(elmText) {
		return document.getElementsByTagName(elmText);
	}

	// obj
	objSelector(selector) {
		return selector;
	}

	// text,html,append,val
	html(htmlTag) {
		if(/(''|""|``|null|undefined|NaN|false)/.test(htmlTag)) return null;
		else {
			this.selector.innerHTML = htmlTag;
		}
	}

	static each(collection=this.selector, callback=(key,value) => {}) {
		return callback(key=key+1, value=collection[key]);
	}

	// event
	ready(callback) {
		this.selector.addEventListener('readystatechange', callback, false);
	}
	on(eventName, callback) {
		this.selector.addEventListener(eventName, callback);
	}
	click(arg1, arg2) {
		if(typeof arg1 === 'function') {
			// bind "this" as selector and just running arg1 as callback
			this.selector.onclick = (e) => arg1;
		}else{
			// set selector with "select" and then run arg2 as callback
			this.select(arg1).onclick = (e) => arg2;
		}
	}
}
function $(selector){
	return new fn(selector);
}

$(document).ready(() => {
	fn.each($('i'), (index, item) => {
		console.log('text');
	});
});