JavaScript(JS) object method - propertyIsEnumerable

The propertyIsEnumerable() method is a built-in method of the JavaScript Object constructor. It checks whether a specific property of an object is enumerable or not.

Here's the syntax:

obj.propertyIsEnumerable(prop)

where obj is the object that we want to check, and prop is the name of the property to check.

This method returns a boolean value indicating whether the specified property is enumerable or not. If the property is enumerable, propertyIsEnumerable() returns true; otherwise, it returns false.

Here's an example that shows how to use the propertyIsEnumerable() method:

const myObj = { prop1: "value1", prop2: "value2" };

console.log(myObj.propertyIsEnumerable("prop1")); // true
console.log(myObj.propertyIsEnumerable("toString")); // false

In this example, we create an object myObj with two properties prop1 and prop2. We use the propertyIsEnumerable() method to check whether the prop1 property is enumerable or not. Since prop1 is an own and enumerable property of the object, propertyIsEnumerable() returns true.

Next, we use the propertyIsEnumerable() method to check whether the built-in toString() method of the object is enumerable or not. Since toString() is not an own property of the object, propertyIsEnumerable() returns false.

The propertyIsEnumerable() method is useful for checking whether a specific property of an object is enumerable or not. Note that this method only checks if a property is enumerable, it does not check if the property exists in the object or if it is inherited from a prototype. For that, you can use the hasOwnProperty() and in operators.