Objects Can Only Use Strings as Keys, While Maps Can Use Anything
Objects Do Not Support Iteration, While Maps Do
forEach. We needed to use additional methods like
Object.keys to assist us. However, the Map object is iterable, so we can directly use
forEach with it.
Objects Have No Order, While Maps Maintain Order
As mentioned earlier, the Map object is iterable, and it has the advantage of maintaining order while iterating. In the past, iterating through a plain object using object methods like
Object.keys did not necessarily return the key-value pairs in the same order in which they were entered. In some cases, such as when writing algorithms, maintaining order is essential, making the Map object much more useful.
Map Provides Many Common Key-Value Pair Methods That Objects Do Not
For example, if we want to know the size of a key-value pair, Map has a
size method that is simple and easy to use. In contrast, if we use a plain object, we may need to use
Object.keys and then use
.length to find out how many keys are in the object. This can be much more cumbersome. Additionally, Map provides a clear method that allows us to delete all key-value pairs at once, whereas we would need to delete each pair individually in a plain object.
In addition to the points mentioned above, there are other subtle differences between Map and plain objects, and their performance varies in different contexts. Interested readers are encouraged to read the following articles: