DOM(ON-OFF)

html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <button id="btn" onclick="greetbtn()">ON</button>
    <script>
        function greetbtn(){
            const inside=document.getElementById("btn");
            console.log(inside.innerText);
            if(inside.innerText=="ON"){
                inside.innerText="OFF";
            }else{
                inside.innerText="ON"
            }
            // inside.innerText="OFF"

        }
    </script>



</body>

</html>