recursion_exercise

Recursion Exercise

Getting started

For this exercise you MUST use recursion to solve these problems. Some of them can be done without, but it is essential that you practice recursion and make the tests pass.

• Write a function called productOfArray which takes in an array of numbers and returns the product of them all

productOfArray([1,2,3]) // 6
productOfArray([1,2,3,10]) // 60

• Write a function called collectStrings which accepts an object and returns an array of all the values in the object that have a typeof string

var obj = {
    stuff: "foo",
    data: {
        val: {
            thing: {
                info: "bar",
                moreInfo: {
                    evenMoreInfo: {
                        weMadeIt: "baz"
                    }
                }
            }
        }
    }
}

collectStrings(obj) // ["foo", "bar", "baz"])

• Write a function called contains that searches for a value in a nested object. It returns true if the object contains that value.

var nestedObject = {
    data: {
        info: {
            stuff: {
                thing: {
                    moreStuff: {
                        magicNumber: 44
                    }
                }
            }
        }
    }
}

contains(nestedObject, 44) // true
contains(nestedObject, "foo") // false

Complete the following CodeWars problems:

• https://www.codewars.com/kata/the-real-size-of-a-multi-dimensional-array/train/javascript
• https://www.codewars.com/kata/sum-squares-of-numbers-in-list-that-may-contain-more-lists/train/javascript
• https://www.codewars.com/kata/recursive-replication

BONUS

• Write a function called search that finds a value in an array and returns the index where the value is at. If the value is not found, the function should return negative 1.

search([1,2,3,4,5],5) // 4
search([1,2,3,4,5],15) // -1

• Refactor your search function to use a faster algorithm called binary search https://www.youtube.com/watch?v=JQhciTuD3E8.

binarySearch([1,2,3,4,5],5) // 4
binarySearch([1,2,3,4,5],15) // -1

• Write a function called stringifyNumbers which takes in an object and finds all of the values which are numbers and converts them to strings. Recursion would be a great way to solve this!

var obj = {
    num: 1,
    test: [],
    data: {
        val: 4,
        info: {
            isRight: true,
            random: 66
        }
    }
}
stringifyNumbers()
/*/
{
    num: "1",
    test: [],
    data: {
        val: "4",
        info: {
            isRight: true,
            random: "66"
        }
    }
}
/*/

Complete this codewars problem!