In our last session, we learned how to access individual items in an array using their index, like
planets[1].

What if we made a mistake or want to update an item in the array?

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Do you think we can change it?

Yes, you can! JavaScript arrays are mutable, meaning their contents can be changed after they are created.

You can replace an item at a specific index with a new value using the assignment operator =.

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How is this similar to assigning a new value to a simple variable?

The syntax is:
arrayName[index] = newValue;

If we have
let planets = ["Mercury", "Venus", "Earth"];
we can change "Venus" to "Mars" like this:
planets[1] = "Mars";

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What index would you use to change "Mercury"?

After running
planets[1] = "Mars";
the planets array would now contain
["Mercury", "Mars", "Earth"].

The original value at that index ("Venus") is replaced by the new one ("Mars").