https://www.jschallenger.com/

JS Challenger Solutions

1. Write a function that takes an array (a) and a value (n) as argument Return the nth element of 'a'

function myFunction(a, n) {
  //code
}
myFunction([1, 2, 3, 4, 5], 3);

Solution

function myFunction(a, n) {
  return a[n - 1];
}
console.log(myFunction([1, 2, 3, 4, 5], 3));

---

2. Write a function that takes two values, say a and b, as arguments. Return true if the two values are equal and of the same type

function myFunction(a, b) {
  //code
}
myFunction(2, 3);

Solution

function myFunction(a, b) {
  return a === b;
}
console.log(myFunction(2, 3));

---

3. Write a function that takes an array (a) as argument. Return the number of elements in a

function myFunction(a) {
  //code
}
myFunction([2, 3, 4, 5]);

Solution

function myFunction(a) {
  return a.length;
}
console.log(myFunction([1, 2, 2, 4]));

---

4. Write a function that a string (a) as argument Create an object that has a property with key 'key' and a value of (a) Return the object

function myFunction(a) {
  //code
}
myFunction("z");

Solution

function myFunction(a) {
  return { key: a };
}
console.log(myFunction("z"));

---

5. Write a function that takes a string as argument. Extract the last 3 characters from the string. Return the result

function myFunction(str) {
  //code
}
myFunction("string");

Solution

function myFunction(str) {
  return str.slice(-3);
}
console.log(myFunction("string"));

---

6. Write a function that takes a string (a) as argument. Extract the first half a. Return the result

function myFunction(a) {
  //code
}
myFunction("string");

Solution

function myFunction(a) {
  return a.slice(0, a.length / 2);
}
console.log(myFunction("string"));

---

7. Write a function that takes a string (a) as argument, Get the first 3 characters of a Return the result

function myFunction(a) {
  //code
}
myFunction("string");

Solution

function myFunction(a) {
  return a.slice(0, 3);
}
console.log(myFunction("string"));

---

8. Write a function that takes an array (a) as argument, Extract the first 3 elements of a Return the resulting array

function myFunction(a) {
  //code
}
myFunction([1, 2, 3, 4, 5]);

Solution

function myFunction(a) {
  return a.slice(0, 3);
}
console.log(myFunction([1, 2, 3, 4, 5]));

---

9. Write a function that takes 'a' value as argument, Return the type of the value

function myFunction(a) {
  //code
}
myFunction([1, 2, 3, 4, 5]);

Solution

function myFunction(a) {
  return typeof a;
}
console.log(myFunction([1, 2, 3, 4, 5]));

---

10. Write a function that takes an array of strings as argument, Sort the array elements alphabetically, Return the result

function myFunction(arr) {
  //code
}
myFunction(["hello", "world", "learning", "js", "is", "fun"]);

Solution

function myFunction(arr) {
  return arr.sort();
}
console.log(myFunction(["b", "c", "f", "e", "d", "a"]));

---

11. Write a function that takes a string (a) and a number (n) as argument. Return the nth character of 'a'

function myFunction(a, n) {
  //code
}
myFunction("javascript", 5);

Solution

function myFunction(a, n) {
  return a.charAt(n - 1); //also a[n-1]
}
console.log(myFunction("javascript", 5));

---

12. Write a function that takes an array (a) as argument, Remove the first 3 elements of 'a', Return the result

function myFunction(a) {
  //code
}
myFunction([1, 2, 3, 4, 5, 6]);

Solution

function myFunction(a) {
  return a.slice(3);
}
console.log(myFunction([1, 2, 3, 4, 5, 6]));

---

13. Write a function that takes an array (a) as argument, Extract the last 3 elements of a, Return the resulting array

function myFunction(a) {
  //code
}
myFunction([1, 2, 3, 4, 5, 6]);

Solution

function myFunction(a) {
  return a.slice(-3);
}
console.log(myFunction([1, 2, 3, 4, 5, 6]));

---

14. Write a function that takes a string (a) as argument, Remove the last 3 characters of a, Return the result

function myFunction(a) {
  //code
}
myFunction("javascript");

Solution

function myFunction(a) {
  return a.slice(0, -3);
}
console.log(myFunction("javascript"));

---

15. Write a function that takes two numbers (a and b) as argument, Sum a and b, Return the result

function myFunction(a, b) {
  //code
}
myFunction(1, 2);

Solution

function myFunction(a, b) {
  return a + b;
}
console.log(myFunction(1, 2));

---

16. Write a function that takes two numbers (a and b) as argument, Return b percent of a

function myFunction(a, b) {
  //code
}
myFunction(20, 40);

Solution

function myFunction(a, b) {
  return (b / 100) * a;
}
console.log(myFunction(20, 40));

---

17. Write a function that takes a string (a) as argument, Remove the first 3 characters of a, Return the result

function myFunction(a) {
  //code
}
myFunction("hello");

Solution

function myFunction(a) {
  return a.slice(3);
}
console.log(myFunction("hello world"));

---

18. Write a function that takes a Set and a value as arguments, Check if the value is present in the Set

function myFunction(set, val) {
  //code
}
myFunction(new Set([1, 2, 3]), 2);

Solution

function myFunction(set, val) {
  return set.has(val);
}
console.log(myFunction(new Set([1, 2, 3]), 2));

---

19. Write a function that takes two strings (a and b) as arguments, Create an object that has a property with key 'a' and a value of 'b', Return the object

function myFunction(a, b) {
  //code
}
myFunction(("name", "pavan"));

Solution

function myFunction(a, b) {
  return { [a]: b };
}
console.log(myFunction("name", "pavan"));

---

20. Write a function that takes 6 values (a,b,c,d,e,f) as arguments, Sum a and b, Then substract by c, Then multiply by d and divide by e, Finally raise to the power of f and return the result, Tipp: mind the order

function myFunction(a, b, c, d, e, f) {
  //code
}
myFunction((6, 2, 1, 4, 2, 3));

Solution

function myFunction(a, b, c, d, e, f) {
  return (((a + b - c) * d) / e) ** f;
}
console.log(myFunction(6, 2, 1, 4, 2, 3));