Salesforce JavaScript Developer Practice Exam

What will be logged when executing the following code? let person = { name: 'Lydia' }; const members = [person]; person = null; console.log(members);

1. null

2. [null]

3. [{}]

4. [{ name: "Lydia" }]

The correct answer is: [{ name: "Lydia" }]

In this scenario, the code creates an object called `person` with a property `name` set to 'Lydia'. It then initializes an array called `members` that contains the `person` object as an element. The important point here is that at this stage, the `members` array holds a reference to the `person` object. When the code sets `person` to `null`, it does not affect the reference stored in the `members` array. The `members` array still holds a reference to the original `person` object, which has its property `name` equal to 'Lydia'. Therefore, when you log `members`, it will show that it contains the object with the name property. Given this understanding, the output logged to the console will be `[{ name: "Lydia" }]`, as it reflects the original object held in the array before the reference to `person` was set to `null`. This illustrates how JavaScript handles object references and the mutability of objects, differentiating between object references and primitive values.