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

<h1>-- 运算符</h1>

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

<script>
var x = 7;
x--;
var z = x;
document.getElementById("demo").innerHTML = z;
</script>

</body>
</html>
运行结果: