摘要：<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width,
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
</head>
<body>
<h4>還能輸入<span id="number">140</span>個字</h4>
<textarea name="" id="text1" ></textarea>
<br>
<input type="button" id="submit" value="發(fā)布">
<script>
var a
document.getElementById('text1').onkeyup=function(){
a = 140 - document.getElementById('text1').value.length;
document.getElementById('number').innerText=a;
if(a<0){
document.getElementById('number').style.color='red';
}else{
document.getElementById('number').style.color='';
}
}
document.getElementById('submit').onclick = function(){
if(a<0){
alert('字數(shù)過多 發(fā)布失敗');
}else{
alert('發(fā)布成功');
}
}
</script>
</body>
</html>利用js鍵盤按下松開事件實時更新字數(shù)
批改老師：查無此人批改時間：2019-05-07 09:35:50
老師總結(jié)：完成的不錯。老師講的案例，要知道用在哪里。這個案例，只要是輸入框，都可以用。繼續(xù)加油。