一 window对象
http://www.w3school.com.cn/jsref/dom_obj_window.asp
二 setInterval的应用
模拟计时器
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<script>
function foo() {
var current_time=(new Date()).toLocaleString()
var ele_input=document.getElementById('d1')
ele_input.value=current_time
}
var ID;
function begining() {
if(ID==undefined){
foo()
ID=setInterval(foo,1000)
}
}
function ending() {
console.log('clear之前ID',ID)
clearInterval(ID)
console.log('clear之后ID',ID)
ID=undefined
}
</script>
</head>
<body>
<input type="text" id="d1"><button onclick="begining()">begin</button><button onclick="ending()">ending</button>
</body>
</html>
输出：
三 value固有属性的三个标签
input标签
textarea标签
select下的option标签
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> </head> <body> <from> <input type="text" value="1"> <textarea name="" cols="30" rows="10" ></textarea> <select name="" id=""> <option value=""></option> </select> </from> </body> </html>