JavaScript Optional Chaining & Nullish Coalescing Explained

What is the benefit of Optional Chaining?

Optional chaining allows you to safely access deeply nested properties without throwing an error if a part of the chain is null or undefined. This prevents your code from crashing or stopping unexpectedly. The operator is a question mark followed by a dot (?.). Use it when a value might not exist but if you're sure a value will always be present, there's no need to use it.

What is the benefit of Nullish Coalescing?

Nullish coalescing (??) is similar to the logical OR operator (||), but it only uses the fallback value if the left-hand side is null or undefined, not for other falsy values like 0, "", or false.

This is useful when you want to provide a default value only when the original value is missing, not when it's just falsy.

Resources

• Optional Chaining MDN
• Nullish Coalescing MDN

Additional Practice

• GitHub Practice Problems - Optional Chaining & Nullish Coalescing