CODEWITHSUNDEEP
javascriptarraysreactjs
VPR
VPR

Reputation: 165

How to enter a string to an array to a given position?

The condition is such that I have to enter a string to an array to a given position such that all the pre position if not exist should be made to be empty strings.

example;

var array = []; // now I want to enter a string 'hello' at index 2

now the array should look like:

array = [ '','','hello']; //now lets say I want to enter a string 'world' at index 4

so the array should become:

array = [ '','','hello','','world'];

Is there a way to do this? or do i have a better option to enter a string and and its position?

Please enlighten me.. :)

Upvotes: 1

Views: 540

Answers (2)

Siva Kondapi Venkata
Siva Kondapi Venkata

Reputation: 11001

  1. First find out how many additional elements need to add ''
  2. push these new elements to array.
  3. push the required value at end.

PS: Assumed the index always higher than the array length. We can add conditions to cover those cases as well.

const insert = (arr, value, index) => {
  arr.push(...new Array(index - arr.length).fill(""));
  arr.push(value);
  return arr;
};

const array = [];

insert(array, "hello", 2);
console.log(array);
insert(array, "world", 4);
console.log(array);

Upvotes: 0

user13278024
user13278024

Reputation:

Something like this should do the trick. The function takes three arguments: the target array, the index (0-based) and the value. Just iterate from the finish of you array to the new position and add "" to each entry, then, after the loop, enqueue the desired string. Here's the fiddle.

let a = ['', '', 'Hello'];

function addStringAtPosition(
  array,
  key,
  value
) {
  for (let i = array.length; i < key; i++) {
    array[i] = '';
  }

  array[key] = value;
}

addStringAtPosition(a, 5, 'World!');

Upvotes: 1

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