What are the differences between ES6 Maps and Objects in JavaScript?

What are the differences between ES6 Maps and Objects in JavaScript?

ES6 Maps and Objects are both key-value data structures, but they have some key differences. Maps can have keys of any type, while Objects can only have strings or symbols as keys. Additionally, Maps maintain the order of their elements, whereas Objects do not guarantee order.

Can you give me an example of when to use a Map instead of an Object?

Sure! Use a Map when you need to maintain the order of entries or when you want to use non-string keys, like objects or functions. For example, if you're implementing a cache where the order of insertion matters, a Map would be ideal.

Are there any performance differences between them?

Yes, Maps generally have better performance for frequent additions and removals of key-value pairs, especially with large datasets. Objects can be slower in these scenarios due to their prototype chain.

What about iteration? How do they differ?

Maps provide built-in methods for iteration, such as map.forEach() and map.entries(), which makes it easier to loop through them. Objects require using for...in or Object.keys() to iterate, which can be less straightforward.