Day 3: Control Structures

This is the day 3 of 30 Days Javascript challenge.

https://courses.chaicode.com/learn/home/30-days-of-Javascript-challenge/30-days-javascript-challenge/section/515627/lesson/3197081

Screenshot :-

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Activity 1: If-Else Statements**

Task 1: Check if a Number is Positive, Negative, or Zero

let number = 10;

if (number > 0) {
  console.log("The number is positive."); // Output: The number is positive.
} else if (number < 0) {
  console.log("The number is negative.");
} else {
  console.log("The number is zero.");
}

This program checks whether a number is positive, negative, or zero and logs the appropriate message to the console.

Task 2: Check Voting Eligibility

let age = 20;

if (age >= 18) {
  console.log("You are eligible to vote."); // Output: You are eligible to vote.
} else {
  console.log("You are not eligible to vote.");
}

This program checks if a person is eligible to vote based on their age and logs the result.

Activity 2: Nested If-Else Statements

Task 3: Find the Largest of Three Numbers

let a = 5;
let b = 8;
let c = 3;

if (a >= b && a >= c) {
  console.log("The largest number is " + a); // Output: The largest number is 8
} else if (b >= a && b >= c) {
  console.log("The largest number is " + b);
} else {
  console.log("The largest number is " + c);
}

This program uses nested if-else statements to find the largest of three numbers and logs the result.

Activity 3: Switch Case

Task 4: Determine the Day of the Week

let dayNumber = 3;
let dayName;

switch (dayNumber) {
  case 1:
    dayName = "Sunday";
    break;
  case 2:
    dayName = "Monday";
    break;
  case 3:
    dayName = "Tuesday";
    break;
  case 4:
    dayName = "Wednesday";
    break;
  case 5:
    dayName = "Thursday";
    break;
  case 6:
    dayName = "Friday";
    break;
  case 7:
    dayName = "Saturday";
    break;
  default:
    dayName = "Invalid day number";
}

console.log(dayName); // Output: Tuesday

This program uses a switch case to determine the day of the week based on a number (1-7) and logs the day name to the console.

Task 5: Assign a Grade Based on Score

let score = 85;
let grade;

switch (true) {
  case score >= 90:
    grade = "A";
    break;
  case score >= 80:
    grade = "B";
    break;
  case score >= 70:
    grade = "C";
    break;
  case score >= 60:
    grade = "D";
    break;
  default:
    grade = "F";
}

console.log("Your grade is " + grade); // Output: Your grade is B

This program uses a switch case to assign a grade based on a score and logs the grade to the console.

Activity 4: Conditional (Ternary) Operator

Task 6: Check if a Number is Even or Odd

let num = 7;
let result = (num % 2 === 0) ? "Even" : "Odd";
console.log(result); // Output: Odd

This program uses the ternary operator to check if a number is even or odd and logs the result to the console.

Activity 5: Combining Conditions

Task 7: Check if a Year is a Leap Year

let year = 2024;
let isLeapYear;

if ((year % 4 === 0 && year % 100 !== 0) || year % 400 === 0) {
  isLeapYear = true;
} else {
  isLeapYear = false;
}

console.log(isLeapYear ? "Leap Year" : "Not a Leap Year"); // Output: Leap Year

This program checks if a year is a leap year using multiple conditions and logs the result to the console.

This guide will help you understand and implement various control structures in JavaScript. Happy coding!