Example of conditional statements in Javascript.

1. If Statement:

 
    let age = 18;
    if (age >= 18) {
      console.log("You are an adult.");
    }   

 
    let isRaining = true;
    if (isRaining) {
        console.log("Remember to take an umbrella!");
    }   

 
    let hour = new Date().getHours();
    if (hour < 12) {
    console.log("Good morning!");
    } else {
    console.log("Good afternoon!");
    }   

2. If-Else Statement:

 
    let temperature = 25;
    if (temperature > 30) {
        console.log("It's hot outside!");
    } else {
        console.log("It's not too hot.");
    }   

 
    let isLoggedIn = false;
    if (isLoggedIn) {
    console.log("Welcome back, user!");
    } else {
    console.log("Please log in to continue.");
    }   

 
    let num = 10;
    if (num % 2 === 0) {
    console.log("The number is even.");
    } else {
    console.log("The number is odd.");
    }   

3. If-Else If-Else Statement:

 
    let score = 85;
    if (score >= 90) {
        console.log("A");
    } else if (score >= 80) {
        console.log("B");
    } else if (score >= 70) {
        console.log("C");
    } else {
        console.log("D");
    } 

 
    llet day = "Sunday";
    if (day === "Saturday") {
        console.log("It's the weekend!");
    } else if (day === "Sunday") {
        console.log("It's still the weekend!");
    } else {
        console.log("It's a weekday.");
    } 

 
    let month = 5;
    if (month === 12 || month === 1 || month === 2) {
        console.log("It's winter.");
    } else if (month >= 3 && month <= 5) {
        console.log("It's spring.");
    } else if (month >= 6 && month <= 8) {
        console.log("It's summer.");
    } else {
        console.log("It's fall.");
    }

4. Ternary Operator (Conditional Operator):

 
    let isStudent = true;
    let message = isStudent ? "You are a student." : "You are not a student.";
    console.log(message);   

let age = 20; let status = age >= 18 ? "Adult" : "Minor"; console.log(status); let score = 78; let result = score >= 60 ? "Pass" : "Fail"; console.log(result);

5. Switch Statement:

 
   let dayOfWeek = 3;
    switch (dayOfWeek) {
    case 1:
        console.log("Monday");
        break;
    case 2:
        console.log("Tuesday");
        break;
    case 3:
        console.log("Wednesday");
        break;
    case 4:
        console.log("Thursday");
        break;
    case 5:
        console.log("Friday");
        break;
    default:
        console.log("Weekend");
    }

 
   let dayOfWeek = "Monday";
    switch (dayOfWeek) {
        case "Monday":
        case "Tuesday":
        case "Wednesday":
        case "Thursday":
        case "Friday":
            console.log("It's a weekday.");
            break;
        case "Saturday":
        case "Sunday":
            console.log("It's the weekend!");
            break;
        default:
            console.log("Invalid day.");
    }

 
    let grade = "A";
    switch (grade) {
        case "A":
            console.log("Excellent!");
            break;
        case "B":
            console.log("Good job!");
            break;
        case "C":
            console.log("Keep it up!");
            break;
        default:
            console.log("You can do better.");
    }

6. For Loop:

 
    for (let i = 1; i <= 5; i++) {
        console.log("Count: " + i);
    }  

7. While Loop:

 
    let count = 0;
    while (count < 5) {
        console.log("While loop iteration: " + count);
        count++;
    } 

8. Do-While Loop:

 
    let num = 0;
    do {
        console.log("Do-While loop iteration: " + num);
        num++;
    } while (num < 5);  

9. Break Statement:

 
    for (let i = 1; i <= 10; i++) {
        if (i === 5) {
            break; // Stop the loop when i is 5.
        }
        console.log("Break loop iteration: " + i);
    } 

10. Continue Statement:

 
    for (let i = 1; i <= 5; i++) {
        if (i === 3) {
            continue; // Skip the current iteration when i is 3.
        }
        console.log("Continue loop iteration: " + i);
    } 

Control flow statements allow you to control the flow of execution in your JavaScript code, making it possible to perform different actions based on specific conditions or iterate over collections of data. These examples demonstrate how to use different types of control flow structures effectively in your JavaScript programs.