How to make array.push() a string multiplied by i

Question

I have been looking for a while for this answer and most results bring up people NOT wanting to push more than once, and its hard to find a straight forward solution / alternative.

I have been tasked with a exercise to output a tower in an array. It increments based on its floor size. For example.

[
  '  *  ', 
  ' *** ', 
  '*****'
]

I am still leaning the ropes of Javascript and I am intrigued to learn, here is what I have come up with:

function towerBuilder(floors) {
  let arr = [];
  let space = " ";
  let tower = "*"  

  for (i = 0; i < floors; i++) {
    arr.push(space, tower * i, space);
  }
    console.log(arr)
}

towerBuilder(3);

console.log shows (Array [ 0, NaN, 0, 0, NaN, 0, 0, NaN, 0 ]) - I guess multiplying a string is a bad idea.

I could probably create multiple for loops and have each push in its own loop, but that would look really messy.

Is there a way to push spaces and *'s multiplied by the for loop?

Thanks

you can't multiply strings, but you can use [`.repeat()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/repeat) — Calvin Nunes, Jan 24 '20 at 11:42
const totalNumberofRows = 5; let output=""; for (let i = 1; i <= totalNumberofRows; i++) { for (let j = 1; j <= i; j++) { output+=j + " "; } console.log(output); output=""; } — R0b1n, Jan 24 '20 at 11:46
You need to get the length of the spaces to surround and the character to stuff in there so `function towerBuilder(floors) { let arr = []; let space = " "; let tower = "*"; let b = floors + 1; while (--b) { let sx = space.repeat(floors - (b)); let tx = tower.repeat(b); let x = sx + tx + sx; arr.push(x); } return arr; } let t = towerBuilder(3);` alert(t); — Mark Schultheiss, Jan 24 '20 at 13:12
This is not truly a duplicate of the marked question given the desired output, voting to re-open. — Mark Schultheiss, Jan 24 '20 at 13:16

vcode · Accepted Answer · 2020-01-24T14:21:48.310

0

 function towerBuilder(floors) {
      let arr = [];
      let tower = '*';
      let space = ' ';
      let total = (2 * floors) + 1;
      for (i = 0; i < floors; i++) {
        let count = (2 * i) + 1;
        let free = (total - count) / 2;
                     arr.push(`${space.repeat(free-1)}${tower.repeat(count)}${space.repeat(free-1)}`);
      }
      console.log(arr)
    }

    towerBuilder(3);

edited Jan 24 '20 at 14:21

answered Jan 24 '20 at 11:49

vcode

453
4
8

this does not put spaces in the strings as the example desired output shows – Mark Schultheiss Jan 24 '20 at 13:10
Question was modified after answer was submitted. Answer corrected. Please undo downvote. – vcode Jan 24 '20 at 14:23
I was able to fix this without any issues so I still consider this the answer. – Tom TK Jan 24 '20 at 14:36
After the answer edit it produces the defined output. I would suggest `i = 0;` instead be `let i = 0;` to avoid a global however. I still consider the question to not be a duplicate of the marked one in the close note but only "related" – Mark Schultheiss Jan 24 '20 at 20:37

How to make array.push() a string multiplied by i

1 Answers1