代码示例:(标识:jsck_oper_not)
<!DOCTYPE html>
<html>
<body>

<p>NOT 运算符 (!) 为 false 语句返回 true,为 true 语句返回 false。</p>

<p id="demo"></p>

<script>
var x = 6;
var y = 3;

document.getElementById("demo").innerHTML = 
!(x === y) + "<br>" + 
!(x > y);
</script>

</body>
</html>
运行结果: