参数分别为 ： 错误信息msg， 错误文件路径url， 列数line， 行数col，错误err
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<script>
window.onerror = function (a , b ,c, d, e) {
console.log(a);
console.log(b);
console.log(c);
console.log(d);
console.log(e);
console.log(arguments);
}
console.log(fnm);
</script>
</body>
</html>
