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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
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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 / Asynchronous Apex

Batchable start

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

12 min read • Intermediate

Batchable start is an atomic Apex topic inside Asynchronous Apex. The example below uses the actual construct named by the lesson rather than a generic placeholder.

Focus on what Batchable start 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-06-04-batchable-start.cls
apex Try It Live 
public class CleanBatch implements Database.Batchable<SObject>{ public Database.QueryLocator start(Database.BatchableContext bc){ return Database.getQueryLocator('SELECT Id FROM Contact'); } public void execute(Database.BatchableContext bc,List<SObject> scope){} public void finish(Database.BatchableContext bc){} }
Edge case / engineering note

Observe when work actually runs, what state crosses the asynchronous boundary, and how completion or failure is surfaced.

Content source & attribution
Original Syntaxis Content · Original Syntaxis Content

Lesson quizzes

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