Сравните неравенство двух операндов.
<!DOCTYPE html>
<html>
<head>
<title>Operator Example</title>
</head>
<body>
<script language="JavaScript">
console.log(" 1 != '1' " + (1 != '1'));
console.log(" 1 !== '2' " + (1 !== '2'));
</script>
</body>
</html>
Fair Fowl