[需要兩次轉譯，因爲/本身也需要轉義
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<input id="btn" type="text">
<script>
let str = '-=+\\[\\]'
let reg = new RegExp(`[${str}]`,'g')
let ele = document.querySelector('#btn');
ele.addEventListener('keyup',e=>{
console.log(ele.value)
if(reg.test(ele.value)){
ele.value = ele.value.replace(reg, "");
console.log('請不要輸入非正常字符')
}
})
</script>
</body>
</html>
