<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>实时控制字数</title>
</head>
<body>
</body>
<script src="jquery-3.2.0.min.js" type="text/javascript" charset="utf-8"></script>
<script type="text/javascript">
function numTip() {
$("#currentNum").text(100 - $("#textArea").val().length);
if($("#textArea").val().length >= 90) {
$("#currentNum").css("color", 'red');
} else {
$("#currentNum").css("color", 'black');
}
}
</script>
</html>
<html>
<head>
<meta charset="UTF-8">
<title>实时控制字数</title>
<style type="text/css">
* {
padding: 0;
margin: 0;
}
.box {
width: 400px;
height: 300px;
margin: 20px auto;
}
.box textarea {
width: 400px;
height: 270px;
font-size: 20px;
}
</style></head>
<body>
<div class="box">
<textarea name="" onkeyup="numTip()" maxlength="100" id="textArea"></textarea>
<p dir="rtl"><span id="currentNum">100</span>/100</p>
</div></body>
<script src="jquery-3.2.0.min.js" type="text/javascript" charset="utf-8"></script>
<script type="text/javascript">
function numTip() {
$("#currentNum").text(100 - $("#textArea").val().length);
if($("#textArea").val().length >= 90) {
$("#currentNum").css("color", 'red');
} else {
$("#currentNum").css("color", 'black');
}
}
</script>
</html>