DOM/input-elements.html

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Input Element</title>
  </head>
  <body>
    <div id="output"></div>
    <script>
      const output = document.getElementById("output");
      output.innerHTML = `
        <h1>Handling Input Element</h1>
        <form name="demoForm">
        <input type="text" name="userName" value="John" />
            </form>
      `;
      const form = document.forms.demoForm;
      const input = form.elements.userName;
      console.log(input);
      input.value = "rakib";
      //   input.disabled = true;
      //   input.readOnly = true;
      console.log(input.value);

      //Events
      input.addEventListener("focus", () => {
        console.log(focus);
        // input.setAttribute("placeholder", "d");
        console.log("focused");
        document.body.style.backgroundColor = "springgreen";
        output.querySelector("h1").innerText = "in focus";
      });
      input.addEventListener("blur", () => {
        console.log(blur);

        console.log("blur");
        document.body.style.backgroundColor = "limegreen";
        output.querySelector("h1").innerText = "out of focus";
      });
      input.addEventListener("input", () => {
        console.log(input);
        console.log("data input");
        document.body.style.backgroundColor = "green";
        output.querySelector("h1").innerText = input.value;
      });
      input.addEventListener("change", () => {
        console.log("data change");
      });

      //auto focus
      input.focus();

      setTimeout(() => input.blur(), 3000);
    </script>
  </body>
</html>