Populating an array in JavaScript with specific values from another array to meet a certain criteria

Question

Populating an array in JavaScript with specific values from another array to meet a certain criteria

Looking to implement a function called populateAnimalArray, which takes an array as input and populates it with additional elements based on another argument specifying the required number.

const animals = ['lion', 'tiger', 'cheetah', 'zebra'];
const animalArr = [];
populateAnimalArray(animals, 6);
// Expected output: ['lion', 'tiger', 'cheetah', 'zebra', 'lion', 'tiger']

The current implementation provided below does not work correctly in all scenarios:

const animals = ['lion', 'tiger', 'cheetah', 'zebra'];
const animalArr = [];


function populateAnimalArray(arr, num) {
  arr.forEach(val => animalArr.push(val));
  let missingElem; //
  if (animalArr.length < num) {
      missingElem = num - animalArr.length;
      console.log('missingElem', missingElem);
      for (let i = 0; i < missingElem; i++) {
          animalArr.push(animals[i]);
      }
  }
  console.log('animalArr', animalArr);
}

populateAnimalArray(animals, 14);

javascript

Answer 1

Answer №1

You may have overcomplicated this task by using unnecessary steps. A simpler approach would be to either slice the array if no is less than arr.length, or push elements using the modulo % operator:

const animals = ['lion', 'tiger', 'cheetah', 'zebra'];
const animalArr = [];


function populateAnimalArray(arr, no) {

    if (no < arr.length) return arr.slice(0, no);
    
    for (let i = 0; i < no; i++) {
    
        animalArr.push(arr[i % arr.length]);
    }
    
    return animalArr;
}

const res = populateAnimalArray(animals, 14);
console.log(res);

Answer 2

You may have overcomplicated this task by using unnecessary steps. A simpler approach would be to either slice the array if no is less than arr.length, or push elements using the modulo % operator:

const animals = ['lion', 'tiger', 'cheetah', 'zebra'];
const animalArr = [];


function populateAnimalArray(arr, no) {

    if (no < arr.length) return arr.slice(0, no);
    
    for (let i = 0; i < no; i++) {
    
        animalArr.push(arr[i % arr.length]);
    }
    
    return animalArr;
}

const res = populateAnimalArray(animals, 14);
console.log(res);

Answer 3

Answer №2

Don't complicate things, just simplify

const animals = ['lion', 'tiger', 'cheetah', 'zebra'];
let newArr = [];
function populateAnimalArray(arr, no) {
  while (arr.length<no) arr = arr.concat(animals); // adding animals until the desired length is reached
  return arr.slice(0,no); // returning the array sliced to the specified length
}
newArr = populateAnimalArray([], 14)
console.log(newArr)
newArr = populateAnimalArray([], 3); // works for shorter arrays too
console.log(newArr)

Answer 4

Don't complicate things, just simplify

const animals = ['lion', 'tiger', 'cheetah', 'zebra'];
let newArr = [];
function populateAnimalArray(arr, no) {
  while (arr.length<no) arr = arr.concat(animals); // adding animals until the desired length is reached
  return arr.slice(0,no); // returning the array sliced to the specified length
}
newArr = populateAnimalArray([], 14)
console.log(newArr)
newArr = populateAnimalArray([], 3); // works for shorter arrays too
console.log(newArr)

Answer 5

Answer №3

One way to achieve this is by using the forEach array function.

const populateAnimalArray = (arr = [], nth) => {
    let newArr = [].concat(arr);
    while (newArr.length < nth) {
        arr.forEach(item => {
            if (newArr.length >= nth) {
                return
            }
            newArr.push(item);
        })
    }
    return newArr;
}

console.log(populateAnimalArray(['lion', 'tiger', 'cheetah', 'zebra'], 14));

Answer 6

One way to achieve this is by using the forEach array function.

const populateAnimalArray = (arr = [], nth) => {
    let newArr = [].concat(arr);
    while (newArr.length < nth) {
        arr.forEach(item => {
            if (newArr.length >= nth) {
                return
            }
            newArr.push(item);
        })
    }
    return newArr;
}

console.log(populateAnimalArray(['lion', 'tiger', 'cheetah', 'zebra'], 14));

Answer 7

Answer №4

You can utilize the array.from method to generate a fresh array containing various animals.

const animals = ['lion', 'tiger', 'cheetah', 'zebra'];
const populateAnimalArray = (animals, length) => {
  return Array.from({length}, (_,i) => animals[i%animals.length]);
}
console.log(populateAnimalArray(animals, 6));
console.log(populateAnimalArray(animals, 2));

.as-console-wrapper { max-height: 100% !important; top: 0; }

Answer 8

You can utilize the array.from method to generate a fresh array containing various animals.

const animals = ['lion', 'tiger', 'cheetah', 'zebra'];
const populateAnimalArray = (animals, length) => {
  return Array.from({length}, (_,i) => animals[i%animals.length]);
}
console.log(populateAnimalArray(animals, 6));
console.log(populateAnimalArray(animals, 2));

.as-console-wrapper { max-height: 100% !important; top: 0; }

Answer 9

Answer №5

It's not functioning properly due to the array length exceeding the specified limit. Here's a solution to address this issue:

const animals = ['lion', 'tiger', 'cheetah', 'zebra'];
const animalArr = [];

function populateAnimalArray(arr, no) {
  arr.map(val => animalArr.push(val));
  let deficitElem; //
  if (animalArr.length < no) {
    deficitElem = no - animalArr.length;
    console.log('deficitElem', deficitElem);
    let j = 0;
    while(j < deficitElem) {
      for (let i = 0; i < animals.length; i++) {
        animalArr.push(animals[i]);
      }
      j += animals.length;
    }
  }
  console.log('animalArr', animalArr);
}

populateAnimalArray(animals, 14);

Answer 10

It's not functioning properly due to the array length exceeding the specified limit. Here's a solution to address this issue:

const animals = ['lion', 'tiger', 'cheetah', 'zebra'];
const animalArr = [];

function populateAnimalArray(arr, no) {
  arr.map(val => animalArr.push(val));
  let deficitElem; //
  if (animalArr.length < no) {
    deficitElem = no - animalArr.length;
    console.log('deficitElem', deficitElem);
    let j = 0;
    while(j < deficitElem) {
      for (let i = 0; i < animals.length; i++) {
        animalArr.push(animals[i]);
      }
      j += animals.length;
    }
  }
  console.log('animalArr', animalArr);
}

populateAnimalArray(animals, 14);

Populating an array in JavaScript with specific values from another array to meet a certain criteria

Answer №1

Answer №2

Answer №3

Answer №4

Answer №5

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