Understanding Apex Data Types in Simple Terms

If you’re learning Salesforce Apex programming, you need to understand data types. Data types define what kind of values a variable can store. Apex, being a strongly-typed language, requires you to declare variables with specific types. Let’s explore the different data types in Apex and how they work.

1. Primitive Data Types

Integer

• What it is: A whole number (no decimal points), like 1, 50, -100.
• Example:Integer count = 10; System.debug(count); // Output: 10
• Use case: Storing counters, ages, or any whole number values.

Long

• What it is: A larger version of Integer for big numbers.
• Example:Long bigNumber = 3000000000L; // Note the 'L' at the end System.debug(bigNumber);
• Use case: Storing large IDs or big financial numbers.

Double

• What it is: A number with decimals (floating-point value), like 3.14 or 99.99.
• Example:Double price = 19.99; System.debug(price);
• Use case: Storing prices, percentages, or any value needing decimal precision.

String

• What it is: Text or characters.
• Example:String greeting = 'Hello, Salesforce!'; System.debug(greeting);
• Use case: Storing names, emails, descriptions, and messages.

Boolean

• What it is: True or false.
• Example:Boolean isActive = true; System.debug(isActive);
• Use case: Flags for conditions (e.g., is the user an admin?).

Date

• What it is: A calendar date without time.
• Example:Date today = Date.today(); System.debug(today);
• Use case: Storing birthdays, deadlines, etc.

Datetime

• What it is: A full timestamp (date + time).
• Example:Datetime now = Datetime.now(); System.debug(now);
• Use case: Tracking when something happened, scheduling events.

Time

• What it is: A time of day without a date.
• Example:Time lunchTime = Time.newInstance(12, 30, 0, 0); System.debug(lunchTime);
• Use case: Storing opening hours, shift times, etc.

ID

• What it is: A unique identifier for Salesforce records.
• Example:Id contactId = '0035g00000ABC123EF'; System.debug(contactId);
• Use case: Working with Salesforce records.

2. sObject Data Types

sObjects represent Salesforce database records, like Account, Contact, or any custom object.

Example:

Account myAccount = new Account(Name = 'Acme Corp');
System.debug(myAccount);

• Use case: Creating and managing records in Apex.

3. Enum Data Type

An Enum is a custom type with a fixed set of values.

Example:

public enum OrderStatus {
    New, Processing, Shipped, Completed, Cancelled
}

OrderStatus currentStatus = OrderStatus.New;
System.debug(currentStatus);

• Use case: Representing limited options (e.g., order statuses, days of the week).

4. Collection Data Types

Collections let you store multiple values in a single variable. Apex has three types:

List (Ordered, Allows Duplicates)

List<String> colors = new List<String>{'Red', 'Blue', 'Red'};
System.debug(colors);

• Use case: Managing groups of records or values.

Set (Unordered, No Duplicates)

Set<Integer> uniqueNumbers = new Set<Integer>{1, 2, 3, 3};
System.debug(uniqueNumbers);  // Output: {1, 2, 3}

• Use case: Ensuring uniqueness (e.g., storing unique emails).

Map (Key-Value Pairs)

Map<String, Integer> scores = new Map<String, Integer>{'Alice' => 90, 'Bob' => 85};
System.debug(scores);

• Use case: Quick lookups (e.g., storing scores by student name).

5. Blob Data Type

A Blob stores binary data (e.g., files, images, encrypted data).

Example:

Blob fileData = Blob.valueOf('Hello Apex');
String base64String = EncodingUtil.base64Encode(fileData);
System.debug(base64String);

• Use case: Working with files, encryption, and APIs.

Conclusion

Understanding data types is the first step to mastering Apex programming. Knowing when to use different types will help you write better, more efficient code in Salesforce. Keep practicing, and soon you’ll be handling Salesforce data like a pro!