jsを使った簡単な照明スイッチのコード

<button>switch light</button>

    <script>

        // window.onload is the window load event, which allows you to write code to the element

        window.addEventListener('load', function () {

            var btn = document.querySelector('button');

            // Define a variable to determine when the light is turned on or off

            var flag = 0;

            btn.onclick = function () {

                if (flag == 0) {

                    document.body.style.backgroundColor = 'black';

                    flag = 1;

                } else {

                    document.body.style.backgroundColor = 'pink';

                    flag = 0;

                }

            }

        })

    </script>

<script>

        var btn = document.querySelector('button');

        var flag = 0;

        btn.onclick = function () {

            if (flag == 0) {

                document.body.style.backgroundColor = 'black';

                flag = 1;

            } else {

                document.body.style.backgroundColor = 'pink';

                flag = 0;

            }

        }

    </script>



<スパン