how to define class in js code example

Example 1: javascript class

class ClassMates{
	constructor(name,age){
    	this.name=name;
      	this.age=age;
    }
  	displayInfo(){
    	return this.name + "is " + this.age + " years old!";
    }
}

let classmate = new ClassMates("Mike Will",15);
classmate.displayInfo();  // result: Mike Will is 15 years old!

Example 2: javascript create class

class Person {
 constructor(name, age) {
   this.name = name;
   this.age = age;
 }
  present = () => { //or present(){
  	console.log(`Hi! i'm ${this.name} and i'm ${this.age} years old`) 
  }
}
let me = new Person("tsuy", 15);
me.present();
// -> Hi! i'm tsuy and i'm 15 years old.

Example 3: javascript classes

//private but is a good example
class includes {
    constructor(){}
  
    inculde_apps(file) { 
      var script  = document.createElement('script'); 
      script.src  = "ext/apps/"+file; 
      script.type = 'text/javascript'; 
      document.getElementsByTagName('body').item(0).appendChild(script);
    } 
    
    inculde_scripts(file) { 
      var script  = document.createElement('script'); 
      script.src  = "ext/scripts/"+file; 
      script.type = 'text/javascript'; 
      document.getElementsByTagName('body').item(0).appendChild(script);
    } 
    
    inculde_css(file) { 
        var script  = document.createElement('link'); 
        script.rel  = "stylesheet"; 
        script.type = 'text/css'; 
        script.href = "css/"+file;
        document.getElementsByTagName('head').item(0).appendChild(script);
    }
  }