The Javascript handler isExtensible() method traps for Object.isExtensible(). It is commonly used for logging or auditing calls.
Syntax:
isExtensible: function(target)
Parameters:
target: It represents the target object.
Return:
Boolean.
Example:
<!DOCTYPE html>
<html>
<body>
<script>
const handler={ too:1 }
const extent = new Proxy(handler, {
isExtensible: function(a) {
document.writeln('HELLO WORLD! : ');
return true;
}});
document.writeln(Object.isExtensible(extent));
</script>
</body>
</html>