test.html

<!DOCTYPE html>
<html>
    <head>
        <title>Test</title>
        <link rel="stylesheet" type="text/css" href="assets/less/test.css" />
        <script>
            function array_demo() {
                var arr = new Array();
                arr[0]="HTML";
                arr[1]="CSS";
                arr[2]="LESS";
                arr[3]="JS";
                arr[4]="PHP";

                document.getElementById("display-array").innerHTML = "Length of the array : " + arr.length;
                
                for(i=0;i<5;i++){
                    document.write(arr[i]);
                }
            }
        </script>
    </head>
    <body>
        <h1>Hello World!</h1>
        <p>
            Lorem ipsum dolor sit amet consectetur adipisicing elit. Eaque placeat libero nobis iure id alias. Natus quod nihil, suscipit consectetur accusantium id quam est praesentium soluta reiciendis, aliquid ipsum? Doloribus.
        </p>
        <button onclick="array_demo()">Show Me</button>
        <p id="display-array">

        </p>
    </body>
</html>