JavaScript is partly an object-oriented language.
To learn JavaScript, we got to learn the object-oriented parts of JavaScript.
In this article, we’ll look at object properties.
We can enumerate properties of an object with the for…in loop.
For example, if we have:
const obj = {
a: 1,
b: 2
};
We can write:
const obj = {
a: 1,
b: 2
};
for (const key in obj) {
console.log(key, obj[key]);
}
Then we get:
a 1
b 2
The key
has the key and obj[key]
has the value.
Not all properties are enumerable, we can set the ebumerable
property descriptor to make a property not enumerable.
We can check with the propertyIsEnumerable()
method to check if a property is enumerable.
We can do the check with:
console.log(obj.propertyIsEnumerable('a'))
then we should get true
since object properties are enumerable unless it’s specified otherwise.
#javascript #programming