Switch Statements in JavaScript

When you have multiple conditions that depend on one value, writing many if...else if statements can become long and difficult to read.

That’s where the switch statement helps.

A switch statement allows you to compare one value with multiple possible cases and run code based on which case matches.

It is commonly used in:

• Menus

• Modes (dark/light)

• Grades

• Status codes

• Day/month names

• User selections

Let’s understand switch in simple words.

Basic Syntax of switch

switch (value) {
    case option1:
        // code
        break;

    case option2:
        // code
        break;

    default:
        // code if no case matches
}

Important:

• case ? a value to match

• break ? stops the switch

• default ? runs when nothing matches

Example 1: Simple Switch Example

let day = 3;

switch (day) {
    case 1:
        console.log("Monday");
        break;

    case 2:
        console.log("Tuesday");
        break;

    case 3:
        console.log("Wednesday");
        break;

    default:
        console.log("Invalid day");
}

Output:

Wednesday

Example 2: Grade System

let grade = "B";

switch (grade) {
    case "A":
        console.log("Excellent");
        break;

    case "B":
        console.log("Very Good");
        break;

    case "C":
        console.log("Good");
        break;

    default:
        console.log("Invalid Grade");
}

Output:

Very Good

Example 3: Menu Selection

let choice = 2;

switch (choice) {
    case 1:
        console.log("Start Game");
        break;

    case 2:
        console.log("Load Game");
        break;

    case 3:
        console.log("Exit");
        break;

    default:
        console.log("Invalid Choice");
}

Output:

Load Game

Example 4: Multiple Cases with Same Output

Sometimes different cases require the same result.

let fruit = "apple";

switch (fruit) {
    case "apple":
    case "banana":
    case "mango":
        console.log("This is a fruit");
        break;

    default:
        console.log("Not a fruit");
}

Output:

This is a fruit

Example 5: Switch With String Comparison

let color = "red";

switch (color.toLowerCase()) {
    case "red":
        console.log("Stop");
        break;

    case "yellow":
        console.log("Ready");
        break;

    case "green":
        console.log("Go");
        break;

    default:
        console.log("Unknown color");
}

Output:

Stop

Example 6: Without break (Fall-through behavior)

If you don’t use break, the next cases will also run.

let x = 2;

switch (x) {
    case 1:
        console.log("One");

    case 2:
        console.log("Two");

    case 3:
        console.log("Three");

    default:
        console.log("Default");
}

Output:

Two
Three
Default

Important:
Always use break unless you want fall-through.

Real-Life Example: Payment Status Code

let status = "SUCCESS";

switch (status) {
    case "SUCCESS":
        console.log("Payment completed");
        break;

    case "FAILED":
        console.log("Payment failed");
        break;

    case "PENDING":
        console.log("Payment pending");
        break;

    default:
        console.log("Unknown status");
}

Output:

Payment completed

Real-Life Example: Month Name

let month = 4;

switch (month) {
    case 1:
        console.log("January");
        break;
    case 2:
        console.log("February");
        break;
    case 3:
        console.log("March");
        break;
    case 4:
        console.log("April");
        break;
    default:
        console.log("Invalid month");
}

Output:

April

Common Mistakes Beginners Make

1. Forgetting break, causing fall-through

2. Using incorrect case type (string vs number)

3. Not using default

4. Confusing uppercase and lowercase comparisons

5. Using switch when simple if/else would be shorter

Example Program (Complete)

let mode = "dark";

switch (mode) {
    case "dark":
        console.log("Dark mode activated");
        break;

    case "light":
        console.log("Light mode activated");
        break;

    default:
        console.log("Unknown mode");
}

Output:

Dark mode activated