Code used in Apex List Tutorial

apexlist.cls

List Data Structure in Apex
-------------------------------

1. Creating a list of Integers

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

List<Integer> numbers = new List<Integer>{10,20,30,40,50,60,70};
System.debug(numbers);

2. Creating a list of Strings

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

3. Adding elements to the list

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

numbers.add(10);
numbers.add(20);
numbers.add(30);
numbers.add(40);

System.debug(numbers);

4. Accessing elements from the list

List<Integer> numbers = new List<Integer>{10,20,30,40,50,60,70};
System.debug(numbers[4]);
// System.debug(numbers[10]);

for(Integer i=0; i<7; i++) {
    System.debug(numbers.get(i));
}

5. Adding element at a particular index in the list

List<Integer> numbers = new List<Integer>{10,20,30,40,50,60,70};
numbers.add(3,80);
System.debug(numbers);

6. Removing element from the list

List<Integer> numbers = new List<Integer>{10,20,30,40,50,60,70};
numbers.remove(2);
System.debug(numbers);


7. Other commonly used list methods:

clear():
----------
List<Integer> numbers = new List<Integer>{10,20,30,40,50,60,70};
System.debug(numbers);
numbers.clear();
System.debug(numbers);

isEmpty():

List<Integer> numbers = new List<Integer>{10,20,30,40,50,60,70};
System.debug(numbers.isEmpty());
numbers.clear();
System.debug(numbers.isEmpty());

size():

List<Integer> numbers = new List<Integer>{10,20,30,40,50,60,70};
System.debug(numbers.size());
numbers.clear();
System.debug(numbers.size());

contains():

List<Integer> numbers = new List<Integer>{10,20,30,40,50,60,70};
System.debug(numbers.contains(50));
System.debug(numbers.contains(100));

sort():

List<Integer> numbers = new List<Integer>{20,30,10,40,60,70,50};
System.debug(numbers);
numbers.sort();
System.debug(numbers);

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