(Salesforce Apex 2024 Release) A Deep Dive into List Element Comparison

 

You can now construct different sort orders in your code by using List.sort() with a Comparator parameter, as the List class now implements the new Comparator interface. For sorting and locale-sensitive comparisons, use the new Collator class's getInstance function. due to the fact that locale-sensitive sorting's outcomes can change depending on who runs the code.

utilizing it in code that anticipates a specific sort order or in triggers, let's see with an example

To sort the employees by name in this example, let's construct a class called Employee with two properties: a name and an id. Since the name property is private, we will use the getName function to retrieve the employee's name.

public class Employee { 
    private Long id; 
    private String name; 

    //Constructor 
    public Employee(Long i, String n){ 
        id=i; 
        name=n; 
    } 
    public String getName() { return name;} 
} 

Now, to add the sorting logic, we will create a class named NameCompare that implements the interface Comparator. We will add the body for the method compare of the Comparator interface, which will take two employees at a time and compare them by name using the help of the compareTo method. This process will continue until all the employees are compared two at a time, and it will return a sorted list of employees.

// Class to compare Employees by name
public class NameCompare implements Comparator<Employee> {
	public Integer compare(Employee e1, Employee e2) {
		if(e1?.getName() == null && e2?.getName() == null) {
		   return 0;
		} else if(e1?.getName() == null) {
			return -1;
		} else if(e2?.getName() == null) {
			return 1;
		}
		return e1.getName().compareTo(e2.getName());
	}
}

Now that the class blueprint is complete, we can utilize it to sort our employees by name. Let's see how it goes.

List<Employee> empList = new List<Employee>();
empList.add(new Employee(101,'Joe Smith', 2020));
empList.add(new Employee(102,'J. Smith', 2020));
empList.add(new Employee(25,'Caragh Smith', 1999));
empList.add(new Employee(105,'Mario Ruiz', 2019));
System.debug(empList);
// Sort by name
Employee.NameCompare nameCompare = new Employee.NameCompare();
empList.sort(nameCompare);
System.debug(empList);

OUTPUT:

The example below sorts a list by default and then uses Collator to sort according to the user's locale. To do this, we first create a user with the locale set to France, and we then apply the sort function to a list of strings. 

string userLocale = 'fr_FR';
User u = new User(Alias = 'standt', Email='standarduser@testorg.com',
EmailEncodingKey='UTF-8', LastName='Testing', LanguageLocaleKey='en_US',
LocaleSidKey=userLocale, TimeZoneSidKey='America/Los_Angeles',
ProfileId = [SELECT Id FROM Profile WHERE Name='Standard User'].Id,
UserName='standarduser' + DateTime.now().getTime() + '@testorg.com');
System.runAs(u) {
List<String> shoppingList = new List<String> {
'épaule désosé Agneau',
'Juice',
'à la mélasse Galette 5 kg',
'Bread', 'Grocery'
};

// Default sort
shoppingList.sort();
Assert.areEqual('Bread', shoppingList[0]);

// Sort based on user Locale
Collator myCollator = Collator.getInstance();
shoppingList.sort(myCollator);
Assert.areEqual('à la mélasse Galette 5 kg', shoppingList[0]);
Assert.areEqual('Bread', shoppingList[1]);
Assert.areEqual('épaule désosé Agneau', shoppingList[2]);

Now that we have list sort functionality exposed instead of just wrapper classes, things will get a lot easier.