Difference Between Method and Function in Salesforce Apex
What is a Method in Apex?
A method in Apex is a block of code that performs a specific task and is always defined inside a class. It can take input parameters, process them, and optionally return a value. Apex methods are always associated with a class, whether it’s a built-in system class or a custom class.
Examples of Built-in Classes and Methods in Apex
| Class | Method |
|---|---|
| Math | Math.max() |
| Math | Math.min() |
| String | String.valueOf() |
| DateTime | DateTime.now() |
| System | System.debug() |
| Decimal | Decimal.valueOf() |
Example of a Method in Apex
Scenario: Create a custom function to find the maximum number without using Math.max().
apex
public class DemoMethod {
public static void findMaximum() {
Integer a = 40;
Integer b = 60;
Integer result = Math.max(a, b);
System.debug(‘Maximum number is: ‘ + result);
}
}
Explanation
• DemoFunction is a custom class.
• findMaximum() is a custom function method created to compare two numbers.
• Math.max(a, b) is a built-in method from the Math class that returns the larger of two numbers.
• System.debug() prints the result to the console (used in Apex to output logs).
What is a Function in Apex?
A function in Apex is technically just a method that performs a specific job and is often custom-built by developers. It can also return a value and take parameters. Apex does not have a separate “function” keyword like some languages (e.g., JavaScript or Python), so functions are written as methods inside classes.
So in Apex, functions = custom methods that perform specific tasks.
Example of a Function in Apex
Scenario: Create a custom function to find the maximum number without using Math.max().
apex
public class DemoFunction {
public static void findMaximum() {
Integer num1 = 10;
Integer num2 = 20;
Integer result = (num1 > num2) ? num1 : num2;
System.debug(‘Maximum number is: ‘ + result);
}
}
Explanation
• DemoFunction is a custom class.
• findMaximum() is a custom function (method) created to compare two numbers.
• The ternary operator checks which number is larger and assigns it to result.
• System.debug() prints the final result, which is 20.
Practice Tasks
Try creating these in your Developer Console or Salesforce Org:
1. Use a built-in method Math.min() to find the smaller number between 20 and 30.
2. Create a custom function to find the sum of two numbers.
3. Use String.valueOf() to convert a number to a string.
4. Create a custom function that checks if a number is even or odd.
5. Use DateTime.now() to display the current date and time.
6. Create a function to return the maximum of three numbers.
7. Use System.debug() to print the result of Decimal.valueOf(‘99.99’).
8. Call a method from a different class using ClassName.MethodName();.
