Setters and Getters

Introduction

• Setters and Getters are methods used to access and update the values of private fields in a class.
• They provide a way to enforce encapsulation and data integrity.

Purpose of Setters and Getters

• Encapsulation: Keep the internal representation of an object hidden from outside manipulation.
• Control: Provide controlled access to the fields of a class.
• Validation: Perform validation before setting a value.
• Read-Only or Write-Only Properties: Make a field read-only or write-only.

Getter Methods

Definition

• Getter Method: A method that retrieves (gets) the value of a private field.
• Naming Convention: Prefix get followed by the field name with the first letter capitalized.

Example

public class Person {
    private String name;
 
    // Getter method for name
    public String getName() {
        return name;
    }
}

Syntax

public ReturnType getFieldName() {
    return fieldName;
}

Characteristics

• No parameters.
• Returns the value of the private field.
• Public access modifier.

Setter Methods

Definition

• Setter Method: A method that updates (sets) the value of a private field.
• Naming Convention: Prefix set followed by the field name with the first letter capitalized.

Example

public class Person {
    private String name;
 
    // Setter method for name
    public void setName(String name) {
        this.name = name;
    }
}

Syntax

public void setFieldName(FieldType fieldName) {
    this.fieldName = fieldName;
}

Characteristics

• Takes one parameter of the field's type.
• No return value (void).
• Public access modifier.

Example with Both Getter and Setter

public class Person {
    private String name;
    private int age;
 
    // Getter for name
    public String getName() {
        return name;
    }
 
    // Setter for name
    public void setName(String name) {
        this.name = name;
    }
 
    // Getter for age
    public int getAge() {
        return age;
    }
 
    // Setter for age
    public void setAge(int age) {
        if (age > 0) {  // Validation check
            this.age = age;
        }
    }
}

Benefits of Using Setters and Getters

• Encapsulation: Hide the internal state of the object.
• Validation: Ensure that the field values are valid (e.g., non-negative age).
• Flexibility: Change the internal implementation without affecting external code.
• Readability: Clarify the purpose of accessing or modifying a field.

Summary

• Getters and Setters are essential for maintaining encapsulation in Java.
• They provide controlled access to private fields and allow for validation and flexibility.
• Following the naming conventions and using these methods consistently leads to clear, maintainable, and robust code.