The delete keyword is used to remove the property and also the value of the property. After deletion, the property cannot be used before it is added back again.
In your example it can be used as -
Example
<html>
<body>
<p id="demo"></p>
<script>
var cricketer = {
name:"John",
rank:3,
points: 800
};
delete cricketer.points;
document.getElementById("demo").innerHTML =
cricketer.name + " scored" + ' '+cricketer.points
</script>
</body>
</html>Output
John scored undefined