Hi I made this a few years back and found it on my drive it was me trying to show how easy it was to make your own jQuery just using basic java code so here it is hope someone finds it usfull.

Code:
// MyLib Version 1.0
// Aurthor Ben J @DreamVB https://github.com/DreamVB
// Last-update : 3 March 2022 21:40pm

const $ = (selector) => {
  // returns the HTML elements that match the selector
  const elements = document.querySelectorAll(selector);
  //Return the elements collection to the $MyLib class
  return new $Mylib(elements, selector);
};

class $Mylib {
  constructor (elements) {
    this._elements = elements;
  }
  
  //Appends HTML to the current element
  append (html){
  	this._elements[0].innerHTML += html;
  	return this;
  }
  
  //Apends HTML to the end of the current element
  prepend (html){
	  this._elements[0].innerHTML = html + this._elements[0].innerHTML;
	  return this;
  }
  
  //Used to add a new class to the elements
  addClass (className) {
	  this._elements.forEach((element) => element.classList.add(className));
	  return this;
  }
  
  //Removes a class from the elements
  removeClass (className) {
	  this._elements.forEach((element) => element.classList.remove(className));
	  return this;
  }
  
  //Return a value eg for text fields
  val(value){
	  if (value !== undefined) {
	  		//Set element value
		  	this._elements[0].value = value;
  	}else{
  			//Return element value.
  			return this._elements[0].value;
  	}
  }
  
  //Returns HTML code from a element
  html(value){
	  if (value !== undefined) {
	  		//Set element HTML code
		  	this._elements[0].innerHTML = value;
  	}else{
  			//Return the HTML code
  			return this._elements[0].innerHTML;
  	}
  }
  
  text(value){
	  if (value !== undefined) {
		  this._elements[0].textContent = value;
	  } else {
		  return this._elements[0].textContent;
	  }
  }
  
  //Sets styles on the elements
  css(value){
	this._elements.forEach((element) => element.setAttribute("style",value));
	return this;
  }
  
  //Return true if a element has a class that matches classname
  hasClass(classname){
	  if (this._elements[0].classList.contains(classname)) {
		  return true;
  	}
  	return false;
  }
  
  hide(){
  	//Hide elements
  	this._elements.forEach((element) => element.style.display = "none");
  }
  
  show(){
  	  //Show elements
	  this._elements.forEach((element) => element.style.display = "block");
  }
  
  attr(name,value){
	  this._elements.forEach((element) => element.setAttribute(name,value));
	  return this;
  }
  
  //Toogle an elements class eg show / hide
  toggleClass (className) {
	  this._elements.forEach((element) => {
		  const classList = element.classList;
		  (classList.contains(className)) ? classList.remove(className) : classList.add(className);
	  });
	  return this;
  }
  //Add an event to a element such as mouse click
  onEvent (event, func){
  	this._elements[0].addEventListener(event,func,false);
  }
  
}