What is a set and a map and how are they different?

What is a set and a map and how are they different?

Duplicate Objects The main difference between List and Set interface in Java is that List allows duplicates while Set doesn't allow duplicates. All implementation of Set honor this contract. While a Map holds two objects per Entry e.g. a key and a value and It may contain duplicate values but keys are always unique.

What is difference between list and set?

Difference between List and Set in Java. List is a type of ordered collection that maintains the elements in insertion order while Set is a type of unordered collection so elements are not maintained any order. List allows duplicates while Set doesn't allow duplicate elements .

What is the difference between list set and map in Salesforce?

Map is a collection of key-value pair. Keys can be any primitive data types (String, Integer, Date, etc) while values can include primitives, Apex objects, sObjects and other collections. Map allows duplicate values, but each key must be unique.

What is list set and map in Java?

List allows to store duplicate elements in java. Set does not allow to store duplicate elements in java. Map stores data in form of key-value pair it does not allow to store duplicate keys but allows duplicate values in java. java.util.List is ordered collection it maintain insertion order in java.