Your First Apex Code

Anonymous Apex is code that runs once without being saved — perfect for experiments, data fixes, and learning.

4.1 Execute Anonymous

Anonymous Apex is code that runs once without being saved — perfect for experiments, data fixes, and learning. Open the Developer Console → Debug → Open Execute Anonymous Window, or put code in scripts/apex/hello.apex and run it from VS Code or the CLI:

Anonymous Apex runs as the current user, respects that user's sharing rules, can perform DML (changes are committed!), and is subject to the same governor limits as any synchronous transaction.

// scripts/apex/hello.apex
String greeting = 'Hello, Apex!';
System.debug(greeting);

Integer total = 0;
for (Integer i = 1; i <= 10; i++) {
    total += i;
}
System.debug('Sum of 1..10 = ' + total);   // 55

sf apex run --file scripts/apex/hello.apex

4.2 Your first class

Deploy it, then call it from Execute Anonymous:

// force-app/main/default/classes/HelloWorld.cls
public with sharing class HelloWorld {

    // a static method — called on the class itself
    public static String greet(String name) {
        if (String.isBlank(name)) {
            return 'Hello, World!';
        }
        return 'Hello, ' + name + '!';
    }
}

System.debug(HelloWorld.greet('Ada'));   // Hello, Ada!
System.debug(HelloWorld.greet(null));    // Hello, World!

4.3 Your first data operation

// create, query, update, delete — the full lifecycle
Account acc = new Account(Name = 'Apex Academy', Industry = 'Education');
insert acc;                                     // DML: acc.Id is now populated
System.debug('New Id: ' + acc.Id);

Account fetched = [SELECT Id, Name, Industry FROM Account WHERE Id = :acc.Id];
fetched.Industry = 'Technology';
update fetched;

delete fetched;                                 // goes to the Recycle Bin

4.4 Your first test

Production deployments require tests. Every class should have one:

@isTest
private class HelloWorldTest {
    @isTest
    static void greetsByName() {
        Assert.areEqual('Hello, Ada!', HelloWorld.greet('Ada'));
    }

    @isTest
    static void greetsWorldWhenBlank() {
        Assert.areEqual('Hello, World!', HelloWorld.greet('  '));
    }
}

sf apex run test --class-names HelloWorldTest --result-format human --code-coverage --wait 10

4.5 Comments and statements

// single-line comment
/* multi-line
   comment */
/**
 * ApexDoc comment — documents classes and methods.
 * @param name the person to greet
 * @return the greeting
 */
Integer x = 5;   // statements end with semicolons; blocks use { }