JavaScript `switch` Statement

🔹 What is the `switch` Statement?

The switch statement in JavaScript is used to execute one block of code from multiple possible cases, based on the value of an expression. It is an alternative to multiple if...else statements.

🔹 Syntax of `switch` Statement

switch (expression) {
    case value1:
        // Code to execute if expression === value1
        break;
    case value2:
        // Code to execute if expression === value2
        break;
    default:
        // Code to execute if no cases match
}

🔹 How `switch` Works

The switch expression is evaluated.
It compares the result with each case value.
If a match is found, the corresponding code block is executed.
The break statement stops execution after a match is found.
If no match is found, the default case (if present) executes.

🔹 Example 1: Basic `switch` Statement

let day = 3;

switch (day) {
    case 1:
        console.log("Monday");
        break;
    case 2:
        console.log("Tuesday");
        break;
    case 3:
        console.log("Wednesday");
        break;
    case 4:
        console.log("Thursday");
        break;
    default:
        console.log("Invalid day");
}

📌 Output: "Wednesday"

Since day = 3, it matches case 3, so "Wednesday" is printed.

🔹 Example 2: Using `default` Case

let color = "blue";

switch (color) {
    case "red":
        console.log("The color is Red.");
        break;
    case "green":
        console.log("The color is Green.");
        break;
    default:
        console.log("Unknown color.");
}

📌 Output: "Unknown color."

Since "blue" doesn't match any case, the default case executes.

🔹 Example 3: Multiple Cases for One Block

let fruit = "apple";

switch (fruit) {
    case "apple":
    case "banana":
        console.log("This is a fruit.");
        break;
    case "carrot":
        console.log("This is a vegetable.");
        break;
    default:
        console.log("Unknown item.");
}

📌 Output: "This is a fruit."

"apple" and "banana" share the same code block.

🔹 When to Use `switch` Instead of `if...else`?

✔ Use switch when checking multiple possible values of a variable.
✔ It makes the code cleaner and more readable than multiple if...else statements.

🔹 Conclusion

switch checks for a match and executes the corresponding code.
break prevents execution from falling into the next case.
default executes if no match is found.
Can group multiple cases for the same output.

JAVASCRIPT

JavaScript switch Statement

🔹 What is the switch Statement?

🔹 Syntax of switch Statement

🔹 How switch Works

🔹 Example 1: Basic switch Statement

🔹 Example 2: Using default Case