I am trying to retrieve the first, and proceeding letters in an array of strings. What I have been working on is looping over each item and then printing arr[i][0], but this does not work for the proceeding letters.

For example:

Input: 
'
00100
11110
10110

Output: 
011010111011000

Basically, I want to traverse vertically, not horizontally.

function solution(s) {
  // transform string into array
  let arr = s.split('\n')

  for (let i = 0; i < arr.length; i  ) {
    // log the first, then proceeding letter in each string
    console.log(arr[i][0])
  }
}

console.log(
  solution(`00100
11110
10110
`)
)

<iframe name="sif1" sandbox="allow-forms allow-modals allow-scripts" frameborder="0"></iframe>

CodePudding user response：

Use a nested for loop:

function solution(s) {
  // transform string into array
  let arr = s.split('\n')

  for (let i = 0; i < arr[0].length; i  ) {
    for(let f = 0; f < arr.length; f  ){
      console.log(arr[f][i])    
    }
  }
}

console.log(solution(`00100
11110
10110`))

<iframe name="sif2" sandbox="allow-forms allow-modals allow-scripts" frameborder="0"></iframe>

CodePudding user response：

You could split and split again for each row and map a new array with the characters transposed.

function solution(s) {
    return s
        .split('\n')
        .reduce((r, s) => [...s].map((c, i) => (r[i] || '')   c), [])
        .join('');
}

console.log(solution('00100\n11110\n10110'));

<iframe name="sif3" sandbox="allow-forms allow-modals allow-scripts" frameborder="0"></iframe>