Apex Reference Guide

Apex Reference Guide
Release Notes
Apex DML Operations
ApexPages Namespace
AppLauncher Namespace
Approval Namespace
Auth Namespace
Cache Namespace
Canvas Namespace
ChatterAnswers Namespace
CommerceBuyGrp Namespace
CommerceExtension Namespace
CommerceOrders Namespace
CommercePayments Namespace
CommerceTax Namespace
commonserviceexcellence Namespace
ComplianceMgmt Namespace
Compression Namespace
ConnectApi Namespace
Context Namespace
Database Namespace
Datacloud Namespace
DataRetrieval Namespace
DataSource Namespace
DataWeave Namespace
Dom Namespace
embeddedai Namespace
EventBus Namespace
ExternalService Namespace
Flow Namespace
Flowtesting Namespace
flowuiruntime Namespace
FormulaEval Namespace
disputemanagement Namespace
fsccashflow Namespace
fsccomplaintmanagement Namespace
fschousehold Namespace
fscserviceprocesses Namespace
fscwmgen Namespace
industriespersonalizedfinance Namespace
Functions Namespace
ise_bots_apex Namespace
IssueCreditMemo Namespace
ind_mfg_sample_mgmt_apex Namespace
industriesNlpSvc
IndustriesDigitalLending Namespace
Invocable Namespace
InvoiceWriteOff Namespace
IsvPartners Namespace
KbManagement Namespace
LxScheduler Namespace
Messaging Namespace
Metadata Namespace
PlaceQuote Namespace
Pref_center Namespace
Process Namespace
QuickAction Namespace
renew_assets_summary Namespace
Reports Namespace
RevSignaling Namespace
RevSalesTrxn Namespace
RichMessaging Namespace
RulesAppln Namespace
runtime_industries_cpq Namespace
runtime_industries_insurance Namespace
Schema Namespace
Search Namespace
setup_flow_performance Namespace
Sfc Namespace
Sfdc_Checkout Namespace
Sfdc_Enablement Namespace
sfdc_surveys Namespace
sfdw Namespace
sfsqlquery Namespace
Site Namespace
Slack Namespace
Support Namespace
System Namespace
AccessLevel Class
AccessType Enum
Address Class
Answers Class
ApexPages Class
Approval Class
Assert Class
AsyncInfo Class
AsyncOptions Class
Blob Class
Boolean Class
BusinessHours Class
CallbackStatus Enum
Callable Interface
Cases Class
Collator Class
Comparable Interface
Comparable Methods
Comparable Example Implementation
Comparator Interface
Continuation Class
Cookie Class
Crypto Class
Custom Metadata Type Methods
Custom Settings Methods
Database Class
Date Class
Datetime Class
Decimal Class
Domain Class
DomainCreator Class
DomainParser Class
DomainType Enum
Double Class
EmailMessages Class
EncodingUtil Class
Enum Methods
EventBus Class
Exception Class and Built-In Exceptions
ExternalServiceTest Class
FeatureManagement Class
Finalizer Interface
FinalizerContext Interface
FlexQueue Class
Formula Class
FormulaRecalcFieldError Class
FormulaRecalcResult Class
Http Class
HttpCalloutMock Interface
HttpRequest Class
HttpResponse Class
Id Class
Ideas Class
InstallHandler Interface
Integer Class
IntegrationTest Class (Developer Preview)
JSON Class
JSONGenerator Class
JSONParser Class
JSONToken Enum
Label Class
Limits Class
List Class
Location Class
LoggingLevel Enum
Long Class
Map Class
Matcher Class
Math Class
Messaging Class
MultiStaticResourceCalloutMock Class
Network Class
Object Class
OrgLimit Class
OrgLimits Class
PageReference Class
Packaging Class
Pattern Class
ParentJobResult Enum
Queueable Interface
QueueableContext Interface
QueueableDuplicateSignature Class
QueueableDuplicateSignature.Builder Class
QuickAction Class
Quiddity Enum
RemoteObjectController
Request Class
ResetPasswordResult Class
RestContext Class
RestRequest Class
RestResponse Class
SandboxPostCopy Interface
Schedulable Interface
SchedulableContext Interface
Schema Class
Search Class
Security Class
SelectOption Class
Set Class
Site Class
SObject Class
SObjectAccessDecision Class
SoqlStubProvider Class
StaticResourceCalloutMock Class
String Class
StubProvider Interface
System Class
Test Class
Time Class
TimeZone Class
Trigger Class
TriggerOperation Enum
Type Class
UninstallHandler Interface
URL Class
UserInfo Class
UserManagement Class
UUID Class
Version Class
WebServiceCallout Class
WebServiceMock Interface
XmlStreamReader Class
XmlStreamWriter Class
TerritoryMgmt Namespace
TxnSecurity Namespace
UserProvisioning Namespace
VisualEditor Namespace
Wave Namespace
Appendices
PDF

Note: This release is in preview. Features described here don’t become generally available until the latest general availability date that Salesforce announces for this release. Before then, and where features are noted as beta, pilot, or developer preview, we can’t guarantee general availability within any particular time frame or at all. Make your purchase decisions only on the basis of generally available products and features.

Comparable Interface

Adds sorting support for Lists that contain non-primitive types, that is, Lists of user-defined types. Your implementation must explicitly handle null inputs in the compareTo() method to avoid a null pointer exception.

Namespace

System

Usage

To add List sorting support for your Apex class, you must implement the Comparable interface with its compareTo method in your class.

To implement the Comparable interface, you must first declare a class with the implements keyword as follows:
Next, your class must provide an implementation for the following method:

The implemented method must be declared as global or public.

Comparable Methods

The following are methods for Comparable.

compareTo(objectToCompareTo)

Returns an Integer value that is the result of the comparison.

Signature

public Integer compareTo(Object objectToCompareTo)

Parameters

  • objectToCompareTo:

    Type: Object

Return Value

Type: Integer

Usage

The implementation of this method returns the following values:

  • 0 if this instance and objectToCompareTo are equal
  • > 0 if this instance is greater than objectToCompareTo
  • < 0 if this instance is less than objectToCompareTo

If this object instance and objectToCompareTo are incompatible, a System.TypeException is thrown.

Comparable Example Implementation

This example implements the Comparable interface. The compareTo method in this example compares the employee of this class instance with the employee passed in the argument. The method returns an Integer value based on the comparison of the employee IDs.
This example tests the sort order of a list of Employee objects.