🚦 Traffic Light System in Java Using Switch Case

🔹 Introduction

In real-world applications, traffic light systems are used to control the flow of vehicles and ensure road safety. In Java, such logic can be implemented using decision-making statements. One of the most suitable statements for this purpose is the switch case, which allows us to execute different actions based on a single input.

In this blog, we will create a Java program that displays the correct action based on the traffic light color.

🔹 Problem Statement

Write a Java program that:
• Accepts a traffic light color as input (red, yellow, or green)
• Displays the corresponding action

Rules:
• Red → Stop
• Yellow → Ready
• Green → Go

If the user enters any other value, the program should display an invalid color message.

🔹 Java Program: Traffic Light System Using Switch Case

import java.util.Scanner;
public class TrafficLightSystem {

    public static void main(String[] args) {
        Scanner scan=new Scanner(System.in);
        System.out.println("Enter traffic light color:");
        String color=scan.nextLine();
        switch(color) {
        case "red":
            System.out.println("Stop");
            break;
        case "yellow":
            System.out.println("Ready");
            break;
        case "green":
            System.out.println("Go");
            break;
        default:
            System.out.println("Invalid color");

        }

    }

}

🔹 Sample Input and Output

Input:

Enter traffic light color : green

Output:

Go