jsclasswithoutconstructor.html


<!DOCTYPE html>
<html>
    <head>
        <link type="stylesheet" src="css/index.css"> <!--link of external css file -->
        <script type="text/javascript" src="js/index.js"></script> <!--link of external JS file -->
    </head>
    <body style="text-align: center;">
        <h1>Welcome To JavaScript Basics</h1>
        <p id="demo"></p>
    </body>
    <script>
        class sname{
            displayFullName = (fname,lname) =>{
                var firstName   =   fname;
                var lastName    =   lname;
                return("<br>"+firstName+" "+lastName+"<br>");
            }
        }
        class result extends sname{
            total_Sub = 7   //without constructor variable declare
            calculate = (num) =>{
                return("got marks: "+(num/7)+"<br>");
            }
        }
        let student1 = new result();
        let student2 = new result();
        var studentdata = [
                        [student1.displayFullName("Krishnendu","Nandy"),student1.calculate(563)],
                        [student2.displayFullName("Rahul","Das"),student2.calculate(583)]
                    ]
        for(var i in studentdata){
            document.write(studentdata[i]);
        }
        // document.getElementById("helloWorld").innerHTML = "Hello!!"; //Change the content of html from JavaScript>
    </script>
</html>