List VS Set In Java: In this article, we will discuss the difference between List and Set in detail i.e.; List v/s Set
Both interfaces directly extend Collection interface, but they are a few differences between them Lets us move on and discuss key differences between them
List vs Set In Java
|It stores elements according to insertion order, insertion order is preserved||Set stores elements in random order, as it uses hashing techniqueInsertion order isn’t preserved|
|While iterating List items, elements will be retrieved as per insertion order||While iterating Set items, elements will be retrieved in random order|
|It allows duplicate elements||Set doesn’t allow duplicate elements i.e.; it stores only unique elementsNote: if the same element is added again, there won’t be any compile-time or runtime error, just that add() method returns false;|
|Any number of the NULL object is allowed to add to the List||Maximum of one NULL is allowed|
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When to use List?
- If the business requirement is to preserve insertion order and
- adding duplicate elements is not a big concern
- then List is the good choice to store the group of elements
- Example: it could be ArrayList or LinkedList or Vector, etc
When to use Set?
- If the business requirement is to avoid storing duplicate elements
- And storing only unique elements
- Where insertion order isn’t a big factor while iterating items
- then Set is the good choice to store the group of elements
- Example: it could be HashSet, etc
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