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Lesson: 04 Collections

Notes

Arrays:

String [] myArray= new List<String>();

Lists:

List<string> myList = new List<string>();

Sets:

Set<string> mySet = new Set<string>();

Maps:

Map<string, string> myMap = new Map<string, string>();

	Lists	Sets	Maps
`add()`	✓	✓
`put()`			✓
`remove()`	✓	✓	✓
`removeAll()`		✓
`size()`	✓	✓	✓
`get()`	✓		✓
`getSObjectType()`	✓		✓
`clear()`	✓	✓	✓
`clone()`	✓	✓	✓
`addAll()`	✓	✓
`contains()`	✓	✓
`containsKey()`			✓
`containsAll()`		✓
`deepClone()`	✓
`equals()`	✓	✓	✓
`indexOf()`	✓
`isEmpty()`	✓	✓	✓
`sort()`	✓
`set()`	✓
`toString()`	✓	✓	✓
`hasCode()`	✓	✓	✓

Convert a List to a Set:

List<String> a = new  List<String>{'A','B','C'};
Set<String> b = new Set<String>(a);
System.debug('List: '+a);
System.debug('Set: ' +b);

Convert a Set to a List:

Set<String> a = new  Set<String>{'A','B','C','A','B','C'};
List<String> b = new List<String>(a);
System.debug('Set: '+a);
System.debug('List: ' +b);

Note: Duplicate elements of the set will not be available in the List.

Exercises

#	Exercise
1	Convert a Set to a List
2	Merge two Lists
3	Convert all the element to UpperCase

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