Code used in set basics apex tutorial on SFDC Stop (https://youtu.be/ENkGqx03sOY)

apexset.cls

Set Data Structure in Apex
-------------------------------

Def: A set is an unordered collection of elements that do not contain any duplicates.

1. Creating a set of Integers

Set<Integer> numbers = new Set<Integer>();
System.debug(numbers);

Set<Integer> numbers = new Set<Integer>{30,30,30,20,20,10};
System.debug(numbers);

2. Creating a set of Strings

Set<String> employees = new Set<String>{'Richard', 'Monica', 'Dinesh', 'Richard'};
System.debug(employees);

3. Adding elements to the set

Set<Integer> numbers = new Set<Integer>();
numbers.add(30);
numbers.add(30);
numbers.add(30);
numbers.add(20);
numbers.add(20);
numbers.add(10);
numbers.add(10);
System.debug(numbers);


4. Accessing elements from the set

Set<Integer> numbers = new Set<Integer>{30,30,30,20,20,10};
System.debug(numbers);

for(Integer num : numbers) {
    System.debug(num);
}

5. Removing element from the set

Set<Integer> numbers = new Set<Integer>{30,30,30,20,20,10};
System.debug(numbers);
System.debug('Removing 20....');
numbers.remove(20);
System.debug(numbers);


6. Checking if the element is present in the set or not

Set<Integer> numbers = new Set<Integer>{30,30,30,20,20,10,40,40};
System.debug(numbers);
System.debug('Is 20 present inside the set? -> ' + numbers.contains(20));
System.debug('Is 100 present inside the set? -> ' + numbers.contains(100));