1 .
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<script>
window.onload=function(){
var id01 = document.getElementById("id01");
alert("根据id查找:"+id01.value);
var inputs = document.getElementsByTagName("input");
alert("根据元素名查找:"+inputs[0].value);
var class01 =document.getElementsByClassName("class01");
alert("根据class查找:"+class01[0].value);
var names1= document.getElementsByName("username");
alert("==根据name属性值=="+names1[0].value);
}
</script>
</head>
<body>
<input type="text" name="username" class="class01" id="id01" value="bluesky"/>
</body>
</html>