Salesforce Introduction to Apex Programming Language

Flow Builder and declarative tools handle most Salesforce automation without code. But some business requirements are too complex, too unique, or too performance-sensitive for point-and-click tools. That is where Apex comes in. Apex is Salesforce's own programming language — built specifically to run on the Salesforce platform and interact with its data.

What Is Apex?

Apex is a strongly typed, object-oriented programming language that runs on Salesforce servers — not on your local machine. It looks and behaves very similarly to Java. If you have written Java before, Apex will feel familiar. If you have not, Apex is a solid first programming language because it is purpose-built and well-documented.

Apex code runs inside Salesforce's cloud infrastructure. You write it in a browser-based editor (or an IDE), and Salesforce compiles and executes it on their servers. Your code has direct, native access to Salesforce data — no HTTP calls needed to read or update records.

The Recipe Book Analogy

  DECLARATIVE (Flow, Validation Rules) = A microwave with preset buttons.
  Fast, easy, works for most meals.

  APEX = A full chef's kitchen with every tool.
  Takes skill, but you can cook anything — exactly the way you want.

When to Use Apex Instead of Flow

Salesforce recommends using declarative tools first. Reach for Apex when:

• The logic is too complex for Flow (nested loops with conditional branching across multiple objects)
• You need to call an external web service and handle the response dynamically
• You need precise control over transaction boundaries and error handling
• Performance requirements are critical and Flow would hit governor limits
• You are building a reusable component or an AppExchange-ready package

Your First Apex Code

Here is a simple Apex class that greets a user by name:

public class GreetingHelper {

    public static String greetUser(String name) {
        String message = 'Hello, ' + name + '! Welcome to Salesforce.';
        return message;
    }

}

Breaking this down:

• public class GreetingHelper — defines a class named GreetingHelper that anyone can access
• public static String greetUser(String name) — a method that takes a name as input and returns a text string
• String message = ... — declares a variable called message and assigns a value to it
• return message; — sends the result back to whoever called this method

Apex Data Types

Every variable in Apex has a type that defines what kind of value it holds:

Control Flow: If, For, While

Apex uses the same control structures as most programming languages:

// IF / ELSE
Integer score = 85;
if (score >= 90) {
    System.debug('Grade: A');
} else if (score >= 75) {
    System.debug('Grade: B');
} else {
    System.debug('Grade: C');
}

// FOR LOOP
List<String> cities = new List<String>{'Delhi', 'Mumbai', 'Bengaluru'};
for (String city : cities) {
    System.debug('City: ' + city);
}

// WHILE LOOP
Integer counter = 1;
while (counter <= 5) {
    System.debug('Count: ' + counter);
    counter++;
}

DML Operations: Working with Salesforce Records

In Apex, you interact with Salesforce data using DML statements — Data Manipulation Language. These are the commands that create, update, or delete records.

// CREATE a new Account
Account newAcc = new Account();
newAcc.Name = 'Tata Motors';
newAcc.Industry = 'Automotive';
newAcc.Phone = '+91-22-6665-8282';
insert newAcc;  // Saves the record to Salesforce

// UPDATE an existing Account
newAcc.AnnualRevenue = 2500000000;
update newAcc;

// DELETE a record
delete newAcc;

DML statements count against Salesforce's Governor Limits — more on this in a later topic. The key rule: never put DML inside a loop. Doing so can hit the 150 DML statements per transaction limit very quickly.

System.debug(): Your Debugging Tool

System.debug() prints a message to the Debug Log — a log file you view in the Developer Console. Use it to inspect variable values and trace the flow of execution while building and testing your code.

Integer qty = 5;
Decimal unitPrice = 499.00;
Decimal total = qty * unitPrice;
System.debug('Total: ' + total);  // Prints: Total: 2495.0

Where You Write Apex

• Developer Console — a browser-based IDE built into Salesforce. Access it from the gear icon → Developer Console.
• VS Code with Salesforce Extensions — the recommended IDE for professional development. Connects to your Salesforce org and provides code completion, linting, and deployment tools.

Key Points

• Apex is Salesforce's own object-oriented programming language, similar to Java, that runs on Salesforce servers.
• Use Apex when declarative tools cannot handle the complexity, performance, or integration requirements of a task.
• Core Apex data types include String, Integer, Decimal, Boolean, Date, Id, List, Map, and Set.
• DML statements (insert, update, delete) interact with Salesforce data — never place them inside loops.
• System.debug() writes to the Debug Log and is the primary tool for tracing and testing Apex code.