InterView: How Set Prevent Duplicates Internally in Java

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Set Interview Questions At bottom of the Article

In Java, a Set is a collection that:

1. Does not allow duplicate elements.
2. Does not maintain any particular order, except for specific implementations like LinkedHashSet or TreeSet

The Set interface is a part of the Java Collections Framework and extends the Collection interface

Common Implementations of Set

1.HashSet

• Does not maintain any specific order of elements.
• Backed by a hash table.
• Provides constant-time performance for basic operations (like add, remove, and contains)

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Set<String> hashSet = new HashSet<>();
hashSet.add("Apple");
hashSet.add("Banana");
hashSet.add("Apple"); // Duplicate, won't be added
System.out.println(hashSet); // Output: [Apple, Banana]

2.LinkedHashSet

• Maintains the order of elements as they are inserted.
• Slightly slower than HashSet because of the additional overhead of maintaining insertion order

Set<String> linkedHashSet = new LinkedHashSet<>()…