What's the difference between a list and a map?

Their names describe their use cases fairly well -- you use a List if you need to list something (probably in some sequential order), while a Map would be used if you need to map an input to an output. You can use a Map as a List by mapping Integers to your elements, but that's overcomplicating things a bit.

What is a list in Java?

Java list: An ordered collection (also known as a sequence). The user of this interface has precise control over where in the list each element is inserted. The user can access elements by their integer index (position in the list), and search for elements in the list. The difference is that they are different.

How to convert a list to a map using Java?

Evidently, we can convert a List to a Map using core Java methods: 4. With Java 8 Starting with Java 8, we can convert a List into a Map using streams and Collectors: 5. Using the Guava Library Besides core Java, we can use third-party libraries for the conversion. 5.1. Maven Configuration

When should I use a list?

Use a List when it makes no sense to do so. Say you had exactly the same student instances but your task was to produce a report of all students' names. You'd put them in a List since there would be no need to pick and choose individual students and thus no need for a Map. that technically isn't correct.