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Core Syntax
Variables Primitive types String methods Lists Sets Maps Enums if statements switch on for loops
Classes & Interfaces
Class declaration Constructor Properties Getters and setters Static members Inheritance virtual and override Interfaces Abstract classes Inner classes
SOQL & SOSL
SOQL query SOQL bind variables Relationship query Aggregate query GROUP BY SOQL for loop Dynamic SOQL SOSL FIND QueryLocator FOR UPDATE
DML
insert update upsert delete undelete Database.insert allOrNone SaveResult Database.rollback Database.setSavepoint Merge records
Triggers
before insert trigger after insert trigger before update trigger after update trigger before delete trigger after undelete trigger Trigger.new Trigger.oldMap Bulkified trigger Trigger handler pattern
Asynchronous Apex
@future Queueable Queueable chaining Batchable start Batchable execute Batchable finish Schedulable System.schedule Platform event publish Transaction finalizer
Security & Sharing
with sharing without sharing inherited sharing Schema describe isAccessible isCreateable stripInaccessible User mode SOQL WITH SECURITY_ENFORCED RunAs in tests
Testing & Integration
@isTest Test.startTest stopTest Test data factory HttpCalloutMock WebServiceMock REST resource HTTP callout JSON.deserialize Custom exception Limits methods
Apex Complete Course / Classes & Interfaces

Constructor

Learn Constructor in Apex with a construct-specific explanation, a unique example, a practical boundary, and a mastery check.

10 min read • Beginner

Constructor is an atomic Apex topic inside Classes & Interfaces. The example below uses the actual construct named by the lesson rather than a generic placeholder.

Focus on what Constructor changes: the input, binding, control path, object state, collection, runtime effect, or language contract. Then alter one value and verify that the behavior changes for a reason specific to this feature.

Topic-specific example

apex-02-02-constructor.cls
apex Try It Live 
public class User { public String name; public User(String n){ name=n; } }
Edge case / engineering note

Change the key input in this Apex example and predict the result first; the named construct should be the reason the behavior changes.

Content source & attribution
Original Syntaxis Content · Original Syntaxis Content

Lesson quizzes

Constructor Mastery Check →
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Class declaration
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Properties