Question 283705 in Javascript Question posted in
A very good W3school tutorial can be found here.

Javascript – Taking the first character of each string in an array to create a new string

I want to take the first character of each item in an array and join those to create a new string. Then i want to do the same with the second characters, third characters, and finally 4th characters.

For example I have the following array:

let arr = ["abcd", "efgh, "ijkl", "mnop"]

would then turn into the string…

"aeim"
"bfjn"
"cgko"
"dhlp"
Tags:

3

Answers


  1. 0

    Assuming that each element in the array has the same length, you could iterate over all indexes and use Array#map and Array#join to construct a string from all the characters at that index.

    (If you want to get the length of the shortest string when they have different lengths, you can use Math.min(...arr.map(s => s.length)).)

    let arr = ["abcd", "efgh", "ijkl", "mnop"];
const res = Array.from({length: arr[0].length}, (_, i) => 
              arr.map(s => s[i]).join(''));
console.log(res);
    Login or Signup to reply.
  2. 0

    You can achieve this by using a combination of the Array#map and Array#join it back to string:

    let arr = ["abcd", "efgh", "ijkl", "mnop"];
let result = Array.from({ length: arr[0].length }, (_, i) =>
  arr.map((item) => item[i]).join("")
);
console.log(result.join("n"));

    Output:

    aeim
bfjn
cgko
dhlp
    Login or Signup to reply.
  3. 0

    Another method is to iterate over each position in the strings with simply two for-loops:

    let arr = ["abcd", "efgh", "ijkl", "mnop"];
let result = [];

for (let i = 0; i < arr[0].length; i++) {
  let currentString = "";
  for (let j = 0; j < arr.length; j++) {
    currentString += arr[j].charAt(i);
  }
  result.push(currentString);
}

console.log(result.join("n"));
    Login or Signup to reply.
Please signup or login to give your own answer.

Back To Top
Search