<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<input type="text" id="user" name="user">
<div></div>
<script>
// 限制8位数字+2位小数点 10000000.00
let div = document.querySelector("div");
let o_val = null;
document.querySelector("[name='user']").
addEventListener("keyup", function () {
let _val = this.value;
let _reg = /^([1-9]d{0,2}).*(d{0,2})$/;
// _val.replace(_reg,search=>{
// return this.value=_val.match(_reg)[1];
// })
let m_val = _val.match(_reg);
if (m_val != null&&parseFloat(m_val)<=100) o_val = m_val;
let k_val = o_val != null ? o_val["input"] : "";
this.value=k_val;
div.innerHTML = k_val;
})
</script>
</body>
</html>