Mastering JavaScript Challenges: Sample Assignments and Solutions

Welcome to our exploration of JavaScript assignments! In this post, we delve into some challenging questions that not only test your understanding but also expand your mastery of JavaScript concepts. As a leading provider of JavaScript assignment help, we believe in empowering students with not just answers but also with the knowledge to tackle complex problems confidently.

Question 1:

You are given an array of integers. Write a function findDuplicate to find the first duplicate number in the array. If there are no duplicates, return -1.

function findDuplicate(nums) {

    let seen = new Set();

    for (let num of nums) {

        if (seen.has(num)) {

            return num;

        } else {

            seen.add(num);

        }

    }

    return -1;

}

// Example usage:

const array1 = [2, 3, 1, 0, 2, 5, 3];

console.log(findDuplicate(array1)); // Output: 2

Solution Explanation:

This solution utilizes a set to keep track of the numbers we've encountered so far. We iterate through the array, and for each element, we check if it's already in the set. If it is, we return it as it's the first duplicate. Otherwise, we add it to the set. If we iterate through the entire array without finding any duplicates, we return -1.

Question 2:

You are given a string containing only digits. Write a function addStrings to add the two strings together and return the sum as a string.

function addStrings(num1, num2) {

    let carry = 0;

    let result = '';

    let i = num1.length - 1;

    let j = num2.length - 1;

    while (i >= 0 || j >= 0 || carry > 0) {

        const digit1 = i >= 0 ? parseInt(num1[i]) : 0;

        const digit2 = j >= 0 ? parseInt(num2[j]) : 0;

        const sum = digit1 + digit2 + carry;

        result = `${sum % 10}${result}`;

        carry = Math.floor(sum / 10);

        i--;

        j--;

    }

    return result;

}

// Example usage:

const num1 = "123";

const num2 = "456";

console.log(addStrings(num1, num2)); // Output: "579"

Solution Explanation:

This solution treats the strings as if they were numbers. It iterates through both strings simultaneously, starting from the least significant digit. It calculates the sum of the current digits along with the carry from the previous addition. The sum is appended to the result string, and any carry is carried forward to the next iteration. Finally, the result string is returned as the sum of the two input strings.

These challenges are designed to enhance your problem-solving skills and deepen your understanding of JavaScript. Whether you're a beginner or an advanced learner, grappling with such problems will undoubtedly sharpen your coding prowess. If you need further assistance or want to explore more challenging assignments, feel free to reach out to us at ProgrammingHomeworkHelp.com.