انها محاولة لنفسك - JavaScript Reference oper

<!DOCTYPE html>
<html>
<body>

<p>y = 5, calculate x = y--, and display y and x:</p>

<button onclick="myFunction()">Try it</button>

<p><strong>Note:</strong> Both variables, y and x, are affected.</p>

<p id="demo1"></p>
<p id="demo2"></p>

<script>
function myFunction() {
   var y = 5;
   var x = y--;
   document.getElementById("demo1").innerHTML = y;
   document.getElementById("demo2").innerHTML = x;
}
</script>

</body>
</html>