Question 218702 in Javascript Question posted in
A very good W3school tutorial can be found here.

How can I return a new array in JavaScript and add to each item in the array? (WITHOUT THE MAP METHOD)

I have to return a new array. Here is the original.

const animals = ['panda', 'turtle', 'giraffe', 'hippo', 'sloth', 'human'];

I have to return a new array where each string is prepended with ‘baby ‘

I need to use a function but I’m not allowed to use the .map() method.

This is the current code I’m running:

function convertToBaby(arr) {
  for (let i = 0; i < arr.length; i++) {
    return `baby ${arr[i]}`;
  }
}

const animals = ["panda", "turtle", "giraffe", "hippo", "sloth", "human"];

console.log(convertToBaby(animals));

I would imagine it returns the new array, but it only returns baby panda.
What is going on?

Tags:

2

Answers


  1. 0

    The return keyword automatically exits the function, so the for loop only returns the first element.

    If you want to use a loop, you can use:

    function convertToBaby(arr) {
  const newArray = [];
  for (let i = 0; i < arr.length; i++) {
    newArray.push(`baby ${arr[i]}`);
  }
  return newArray;
}
    Login or Signup to reply.
  2. 0

    Try using Array.reduce.

    const parents = ['panda', 'turtle', 'giraffe', 'hippo', 'sloth', 'human'];
const babies = parents.reduce( (acc, v) => [...acc, `baby${v}`], []);

console.log(`${parents}n${babies}`);

    Or by looping (notice the return position):

    const parents = ['panda', 'turtle', 'giraffe', 'hippo', 'sloth', 'human'];
const babies = babiesOf(parents);

console.log(`${parents}n${babies}`);

function babiesOf(animals) {
  const babies = [];
  
  for (let i = 0; i < animals.length; i += 1) {
    babies[i] = `baby${animals[i]}`;
  }
  // return should be out of the loop
  return babies;
}
    Login or Signup to reply.
Please signup or login to give your own answer.

Back To Top
Search