cachnhungjsvaohtml.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>


<h1 id="demo">A Web Page</h1>

<input type="button" onclick="changeable()" value="click to change">


<h2 id="demo2">A Web Page 2</h2>

<input type="button" id="demo2" value="click to change 2">

<br>
<button onclick="alert('Xin chào bạn!');">Click me</button>
</body>

<p id="demoX">Click here to change me</p>
<button type="button" onclick='document.getElementById("demoX").innerHTML = "Hello js!"'>cick to me!</button>


<script type="text/javascript">

    function changeable() {
        document.getElementById("demo").innerHTML = "here is new text file";

    }

    var changetext = document.getElementById("demo2");
    changetext.addEventListener("click", func_change);

    function func_change() {
        document.getElementById("demo2").innerHTML = "here is second way to change text";
    }


</script>


</html>