JavaScript Conditional Statements 🌟

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JavaScript Conditional Statements 🌟
Conditional statements allow us to execute different code based on conditions.

1️⃣ Types of Conditional Statements
Statement Description
if Executes a block of code only if a condition is true.
else Executes a block of code if the if condition is false.
else if Adds multiple conditions between if and else.
switch Checks multiple possible values of a variable.

2️⃣ if, else if, and else Statements

✅ 1. Basic if Statement
Executes code only when the condition is true.

let age = 20;



if (age >= 18) {

    console.log("You are an adult.");

}

// Output: "You are an adult."

✅ 2. if-else Statement
Provides an alternative code block if the condition is false.

let age = 15;



if (age >= 18) {

    console.log("You can vote.");

} else {

    console.log("You cannot vote.");

}

// Output: "You cannot vote."

✅ 3. else if for Multiple Conditions

let score = 85;



if (score >= 90) {

    console.log("Grade: A");

} else if (score >= 80) {

    console.log("Grade: B");

} else if (score >= 70) {

    console.log("Grade: C");

} else {

    console.log("Grade: F");

}

// Output: "Grade: B"

📌 Best Practice:
✅ Check conditions from most specific to least specific to avoid unnecessary checks.

3️⃣ switch Statement (Better than Multiple if-else)
Instead of multiple if-else, we use switch for checking exact values.

✅ 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;

    default:

        console.log("Invalid day");

}

// Output: "Wednesday"

📌 Why break?

Without break, the code continues executing the next cases.

The default case runs if no match is found.

✅ 2. switch with Multiple Cases
We can group cases together when they share the same output.

let fruit = "apple";



switch (fruit) {

    case "apple":

    case "banana":

    case "orange":

        console.log("This is a fruit.");

        break;

    default:

        console.log("Unknown item.");

}

// Output: "This is a fruit."

4️⃣ Best Practices
✅ Use if-else for ranges or conditions (x > 10, y === 5 && z < 3).
✅ Use switch for specific values (case 1, case 'apple').
✅ Always include break in switch to prevent unintended execution.

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    Date: 2025-03-29 00:00:00.000000