Constructor & Conditional Statements in Salesforce

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Constructor in Salesforce

A constructor is a unique method that is used to create and initialize an instance/Object of a class. When an object is created from a class, the constructor is automatically called to initialize the object’s state and properties.

The constructor does not have any return type.
The name of the constructor must be the same as the Class Name.
The parent class(topmost class) constructor should always be public.
- Private in cases where the methods are class methods.

				
					Example:- 
Animal dog = new Animal();

Where - 
Animal - Class
dog - the variable name of the Object
= - Assignment operator
new - keyword
Animal() - constructor

Types of Constructor

There are two types of constructors in Salesforce:

Default Constructor: A default constructor is a constructor that is automatically created by Salesforce if no other constructor is defined in the class.
- The default constructor takes no arguments and does not perform any initialization.
A parameterized constructor is a constructor that takes one or more parameters and uses them to initialize the object’s state and properties.
- When you want to enforce that user must need to pass the value while creating the instance/Object.
- Parameterized constructors are useful for setting initial values or default values for object properties.
  - Animal dog = new Animal(‘Paremrian’);

				
					public List<String> stateList;
pubic StatePicker(String countryName){
    stateList = {'','',''};
}

				
					
<Access Modifier> <Class Name> (<Parameters>) {
  // Constructor Body
}

public class MyObject {
  public String name;
  public String description;

  public MyObject(String objectName, String objectDescription) {
    this.name = objectName;
    this.description = objectDescription;
  }
}

Conditional Statements

Conditional Statements
- If else
- Switch

Use the “if-else” statement in Apex code to execute different blocks of code based on a condition

				
					if (condition) {
    // code block to execute if the condition is true
} else {
    // code block to execute if the condition is false
}

if (condition) { // boolean (TRUE/FALSE)
    // code block to execute if the condition is true
} else if(condition) {
    // code block to execute if the condition is false
} else {

}
// Example 1
Integer x = 5;
if (x > 10) { // <, = , >=, <=, != <>
    System.debug('x is greater than 10');
} else {
    System.debug('x is less than or equal to 10');
}

Integer x = 5;
if (x > 10) { // <, = , >=, <=, != <>
    System.debug('x is greater than 10');
} else if(x >= 5) {
    System.debug('x is greater than or equal to 5');
} else{
    System.debug('x is less than 5');
}

// Example 2
String fruit = 'banana';
if (fruit == 'apple') {
    System.debug('This is an apple');
} else if (fruit == 'orange') {
    System.debug('This is an orange');
} else {
    System.debug('This is neither an apple nor an orange');
}

Switch Statement in Salesforce

You can use the “switch” statement in Apex code to execute different blocks of code based on the value of a variable.
The syntax for the “switch” statement is as follows:

				
					switch on expression {
    when value1 {
        // code block to execute if expression equals value1
    }
    when value2 {
        // code block to execute if expression equals value2
    }
    when value3 {
        // code block to execute if expression equals value3
    }
    when else {
        // code block to execute if the expression does not equal any of the specified values
    }
}

Here’s an example of how to use the “switch” statement in Apex code:

				
					String fruit = 'banana';
switch on fruit {
    when 'apple' {
        System.debug('This is an apple');
    }
    when 'orange' {
        System.debug('This is an orange');
    }
    when 'banana' {
        System.debug('This is a banana');
    }
    when else {
        System.debug('This is not an apple, orange, or banana');
    }
}

Hands-on Code

				
					public class Laptops {
    /* Instance Variable / Object Variable */
    public String companyName; // default value ~= null
    public Boolean isAdult; // default value ~= null
    public String processor;
    public Integer ramSize;
    
    /* Class Variable / Static Variable */
    public static String name;
    /*
    public Laptops(){
    }
    */
    // Account acc = new Account(Name ='Test Account');
    // Account acc = new Account(Name ='Test Account', Industry='Education');
    public Laptops(Integer ramSize){
        this.ramSize = ramSize;
        // this.ClassVariableName = <constructor parameter name>
    }
    public Laptops(String companyName){
        System.debug('Company Name in constructor is =>'+ companyName);
        this.companyName = companyName;
        // this.ClassVariableName = <constructor parameter name>
    }
    public Laptops(String companyName, String processor){
        System.debug('Company Name in constructor is =>'+ companyName);
        this.companyName = companyName;
        this.processor = processor;
    }
    public Laptops(String companyName, String processor, Integer ramSize){
        System.debug('Company Name in constructor is =>'+ companyName);
        this.companyName = companyName;
        this.processor = processor;
        this.ramSize = ramSize;
    }
    
    public void listAllLaptops(){
       // SOQL
    }
    // Instance Method / Object Method
    public void printCompanyName(){
        
        System.debug(' Company Name withing printCompanyName method is => '+ companyName);
        System.debug(' Company Name withing printCompanyName method is => '+ name);
        
        if(companyName != null){
            
            System.debug(' Company Name withing printName method is => '+ name);
            // SOQL - SELECT ID, Name, ----- FROM Laptop__c WHERE Company_Name = ''
            
        } else if( companyName != null && processor != null ){ // && = AND, || = OR 
            
            System.debug(' companyName withing printName method is => '+ companyName);
            System.debug(' processor withing printName method is => '+ processor);
            // SOQL - SELECT ID, Name, ----- FROM Laptop__c WHERE Company_Name = '' AND Processor__c = ''
             
        } else if(companyName != null && processor != null && ramSize != null){
            
            System.debug(' companyName withing printName method is => '+ companyName);
            System.debug(' processor withing printName method is => '+ processor);
            System.debug(' ramSize withing printName method is => '+ ramSize);
            // SOQL - SELECT ID, Name, ----- FROM Laptop__c WHERE Company_Name = '' AND Processor__c = '' AND RAM_SIZE__c = 784;
             
        } else if(companyName != null || processor != null || ramSize != null){
            
            //
            
        } else {
            
        }
    }
    // Class Method / Static Methods
    public static void printName(){
        // Static Variable/Class Variable
        
    }
    
}

				
					//Laptops apple = new Laptops('Apple');
//apple.printCompanyName();
Laptops.name = 'Apple';
Laptops.printName();

String fruit = 'bananat632';
switch on fruit {
    when 'apple' {
        System.debug('This is an apple');
    }
    when 'orange' {
        System.debug('This is an orange');
    }
    when 'banana' {
        System.debug('This is a banana');
    }
    when else {
        System.debug('This is not an apple, orange, or banana');
    }
}

Integer x = 56;
Integer y = 10;
Integer z = (x / y);// +, - , /, *, %
System.debug(' '+z);

Assignment

Create a class “Car” that should have the following

The class should have the private variables
- Name
- Model
- Year
- Company
- Type
Create multiple constructors that are accepting the different parameters
- Car(String name, String type)
- Car(String name)
- Car( )
- Car(String name, String model, String year, String company, Type)
- Car(Integer year)
Within the constructors assign the values to the private variables. Note: – The value should be assigned to the variable that is passed in the constructor and for other variables assign a blank value. See the example below
- public Car(String year){
  this.year = year;
  this.name = ”;
  this.model = ”;
  this.company = ”;
  this.type = ”;
  }
Create various methods to print the Car Details
- printCarInformation( ) → This method should print all the information about the Car
- printCarName( ) → This method should only print the name of the Car
- printCarYear( ) → This method should only print the built year of the Car
- printCarNameType( ) → This method should only print the name & type of the Car