arrayDepth function

arrayDepth.js

// 1 - (a) Reimplement Array.prototype.forEach as a standalone function that accepts an array and a callback
//     (b) Invoke the function such that it logs the array's values individually on each line
//     (c) Invoke the function such that it logs the array's indices individually on each line

const numberArrayOne = [1, 2, 3, 4, 5]

function forEach(list, cb) {
    for (let i = 0; i < list.length; i++) {
        cb(list[i], i, list)
    }
}

// forEach(numberArrayOne, (number, index, list) => {
//   console.log(number)
// })


// 2 - (a) Reimplement Array.prototype.map as a standalone function that accepts an array and a callback
//     (b) Invoke the function such that it returns an arraay with each value incremendted by 2.
//     (c) Invoke the function such that it returns an arraay with each index incremendted by 1.

function map(list, cb) {
    const newList = [];

    for (let i = 0; i < list.length; i++) {
        newList.push(cb(list[i], i, list))
    }

    return newList
}

const newList = map(numberArrayOne, (number, index, list) => {
    return number + 2
})

// console.log(newList)

const newListTwo = map(numberArrayOne, (number, index, list) => {
    return index + 1
})

// console.log(newListTwo)

// 3 - Write a function 'arrayDepth' that given an array of arbitrarily nested arrays, return n,  where n is the deepest level that contains a non-array value.

function arrayDepth(list, depth = 0) {
    // Base Case(s): return depth
    if (!Array.isArray(list)) {
        return depth
    }

    if (list.length === 0) {
        return 0;
    }

    // Recursive: 
    const depthList = list.map(item => {
        return arrayDepth(item, depth + 1)
    })

    return Math.max(...depthList)
}



const arr0 = [50]          // => 1
const arr1 = [10, 20, 30, 40 ]          // => 1 
const arr2 = [[5], [[]]]                // => 2
const arr3 = [[10, 20 ], [[30, [40]]]]  // => 4
const arr4 = []                         // => 0
const arr5 = [[[]]]                     // => 0

console.log("Depth 1: ", arrayDepth(arr0))
console.log("Depth 1: ", arrayDepth(arr1)) 
console.log("Depth 2: ", arrayDepth(arr2))
console.log("Depth 4: ", arrayDepth(arr3))
console.log("Depth 0: ", arrayDepth(arr4))
console.log("Depth 0: ", arrayDepth(arr5))