Are you a student grappling with complex JavaScript assignments, searching for reliable assistance to navigate through intricate coding challenges? Look no further. At ProgrammingHomeworkHelp.com, we specialize in providing comprehensive support for JavaScript assignments, offering both guidance and exemplary solutions to empower students in mastering this versatile programming language. In this post, we delve into two master-level JavaScript questions, each accompanied by a meticulously crafted solution by one of our seasoned experts. Whether you're struggling with concepts like closures or object-oriented programming, our solutions will illuminate the path to clarity and proficiency. Let's dive in!

Question 1

Implement a function called "uniqueValues" that takes an array of numbers as input and returns an array containing only the unique values from the input array. Ensure that the order of the unique values in the output array remains the same as their order of appearance in the input array.

Solution 1

function uniqueValues(arr) {
  return arr.filter((value, index, array) => array.indexOf(value) === index);
}

// Test the function
const inputArray = [1, 2, 3, 4, 2, 3, 5, 6, 1];
console.log(uniqueValues(inputArray)); // Output: [1, 2, 3, 4, 5, 6]

Explanation:

In this solution, we utilize the filter method to iterate over the input array (arr). For each element (value), we check if its index (array.indexOf(value)) matches the current index (index). If they are equal, it indicates that the element is unique in the array, and thus, it is retained in the filtered array.

Question 2

Write a JavaScript class called "Calculator" that has methods to perform basic arithmetic operations such as addition, subtraction, multiplication, and division. The class should maintain an internal state to store the result of the calculations, and each method should update this state accordingly. Additionally, implement a method called "getResult" to retrieve the current result.

Solution 2

class Calculator {
  constructor() {
    this.result = 0;
  }

  add(num) {
    this.result += num;
  }

  subtract(num) {
    this.result -= num;
  }

  multiply(num) {
    this.result *= num;
  }

  divide(num) {
    if (num !== 0) {
      this.result /= num;
    } else {
      throw new Error("Division by zero is not allowed.");
    }
  }

  getResult() {
    return this.result;
  }
}

// Test the Calculator class
const calculator = new Calculator();
calculator.add(5);
calculator.subtract(2);
calculator.multiply(3);
calculator.divide(3);
console.log(calculator.getResult()); // Output: 3

Explanation:

This solution demonstrates the implementation of a Calculator class in JavaScript. Upon instantiation, the class initializes the result property to 0. Each arithmetic method (add, subtract, multiply, divide) updates the result property based on the operation performed with the input number (num). The getResult method simply returns the current value of the result property.

Conclusion

Mastering JavaScript involves understanding its fundamental concepts and applying them effectively to solve diverse programming challenges. By exploring the solutions to these master-level JavaScript questions, we hope to enhance your proficiency and confidence in tackling similar assignments. At ProgrammingHomeworkHelp.com, our team of experts is dedicated to providing unparalleled assistance and guidance to support your academic journey. If you need help with JavaScript assignment or wish to explore more advanced topics, don't hesitate to reach out. Let's embark on this coding adventure together!