Getters & Setters

Overview

Getters (Accessors) and Setters (Mutators) are public methods used to read and update private variables. They allow the class to enforce rules and validation whenever data is accessed or changed.

Syntax

cpp

class User {
private:
    string password;

public:
    // Setter
    void setPassword(string pwd) {
        if (pwd.length() >= 8) {
            password = pwd;
        }
    }
    
    // Getter
    string getPassword() const {
        return password;
    }
};

Common Pitfalls

Writing a getter/setter for *every single* private variable blindly. If a variable is truly internal, it shouldn't have public accessors at all.

Interview Tips

Always mark getters as `const` (e.g., `int getAge() const;`). This tells the compiler the method will not modify the object, allowing getters to be called on `const` object instances.

Real-World Example

Using getters/setters for data validation.

example

cpp

#include <iostream>
using namespace std;

class Employee {
private:
    int salary;

public:
    void setSalary(int s) {
        if (s >= 30000) {
            salary = s;
        } else {
            cout << "Invalid salary.\n";
        }
    }
    
    int getSalary() const {
        return salary;
    }
};

int main() {
    Employee emp;
    emp.setSalary(20000); // Fails validation
    emp.setSalary(50000); // Succeeds
    cout << emp.getSalary() << endl;
    return 0;
}

Take C++ Quiz