Day 5 function.js

// Activity 1: Function Declaration

// Task 1: Write a function to check if a number is even or odd and log the result to the console.

function checkEvenOdd(number) {
    if (number % 2 === 0) {
        console.log(`${number} is even`);
    } else {
        console.log(`${number} is odd`);
    }
}

checkEvenOdd(5); 
checkEvenOdd(8); 


// Task 2: Write a function to calculate the square of a number and return the result.

function squareNumber(number) {
    return number * number;
}

console.log(squareNumber(4)); 
console.log(squareNumber(7)); 


//Activity 2: Function Expression

// Task 3: Write a function expression to find the maximum of two numbers and log the result to the console.

const findMax = function(num1, num2) {
    const max = num1 > num2 ? num1 : num2;
    console.log(`The maximum of ${num1} and ${num2} is ${max}`);
}

findMax(5, 8); 
findMax(12, 3); 


// Task 4: Write a function expression to concatenate two strings and return the result.

const concatenateStrings = function(str1, str2) {
    return str1 + str2;
}


console.log(concatenateStrings("Hello, ", "world!")); 
console.log(concatenateStrings("Good ", "morning")); 


// Activity 3: Arrow Functions

// Task 5: Write an arrow function to calculate the sum of two numbers and return the result.

const sumNumbers = (num1, num2) => num1 + num2;


console.log(sumNumbers(5, 3)); 
console.log(sumNumbers(10, 7)); 


//Task 6: Write an arrow function to check if a string contains a specific character and return a boolean value.

const containsCharacter = (str, char) => str.includes(char);


console.log(containsCharacter("hello", "e")); // true
console.log(containsCharacter("world", "a")); // false


// Activity 4: Function Parameters and Default Values

// Task 7: Write a function that takes two parameters and returns their product. Provide a default value for the second parameter.

function multiplyNumbers(num1, num2 = 1) {
    return num1 * num2;
}

console.log(multiplyNumbers(5, 3)); 
console.log(multiplyNumbers(7)); 


//Task 8: Write a function that takes a person’s name and age and returns a greeting message. Provide a default value for the age.

function greetPerson(name, age = 18) {
    return `Hello, ${name}! You are ${age} years old.`;
}

console.log(greetPerson("Sourabh", 21)); 
console.log(greetPerson("sink")); 


//Activity 5: Higher-Order Functions

// Task 9: Write a higher-order function that takes a function and a number, and calls the function that many times.

function repeatFunction(fn, times) {
    for (let i = 0; i < times; i++) {
        fn();
    }
}


repeatFunction(() => console.log("Hello!"), 3);



// Task 10: Write a higher-order function that takes two functions and a value, applies the first function to the value, and then applies the second function to the result.

function applyFunctions(fn1, fn2, value) {
    return fn2(fn1(value));
}

const double = x => x * 2;
const increment = x => x + 1;

console.log(applyFunctions(double, increment, 5));