Using the in
operator, you can
check for the presence of a property
in an object. Let's look at an example.
Suppose we are given such an object:
let obj = {a: 1, b: 2, c: 3};
Let's check if our object has some property:
console.log('b' in obj); // shows true
Now let's check for a non-existent property:
console.log('x' in obj); // shows false
Tell me, what will be output to the console as a result of executing the following code:
let obj = {x: 1, y: 2, z: 3};
console.log('x' in obj);
console.log('w' in obj);