freeCodeCamp/curriculum/challenges/english/08-coding-interview-prep/rosetta-code/align-columns.english.md

---
title: Align columns
id: 594810f028c0303b75339ad0
challengeType: 5
---

## Description
<section id='description'>
<p>Given a text file of many lines, where fields within a line are delineated by a single <code>$</code> character, write a program that aligns each column of fields by ensuring that words in each column are separated by at least one space. Further, allow for each word in a column to be either left justified, right justified, or center justified within its column.</p>
<p>Use the following text to test your programs:</p>
<pre>
Given$a$text$file$of$many$lines
where$fields$within$a$line$
are$delineated$by$a$single$'dollar'$character
write$a$program
that$aligns$each$column$of$fields
by$ensuring$that$words$in$each$
column$are$separated$by$at$least$one$space.
Further,$allow$for$each$word$in$a$column$to$be$either$left$
justified,$right$justified
or$center$justified$within$its$column.
</pre>
<p>Note that:</p>
The example input texts lines may, or may not, have trailing dollar characters.
All columns should share the same alignment.
Consecutive space characters produced adjacent to the end of lines are insignificant for the purposes of the task.
Output text will be viewed in a mono-spaced font on a plain text editor or basic terminal.
The minimum space between columns should be computed from the text and not hard-coded.
It is not a requirement to add separating characters between or around columns.
</section>

## Instructions
<section id='instructions'>

</section>

## Tests
<section id='tests'>

```yml
tests:
  - text: <code>formatText</code> is a function.
    testString: 'assert(typeof formatText === ''function'', ''<code>formatText</code> is a function.'');'
  - text: '<code>formatText</code> with the above input and "right" justification should produce the following: '
    testString: 'assert.strictEqual(formatText(testInput, ''right''), rightAligned, ''<code>formatText</code> with the above input and "right" justification should produce the following: '');'
  - text: '<code>formatText</code> with the above input and "left" justification should produce the following: '
    testString: 'assert.strictEqual(formatText(testInput, ''left''), leftAligned, ''<code>formatText</code> with the above input and "left" justification should produce the following: '');'
  - text: '<code>formatText</code> with the above input and "center" justification should produce the following: '
    testString: 'assert.strictEqual(formatText(testInput, ''center''), centerAligned, ''<code>formatText</code> with the above input and "center" justification should produce the following: '');'

```

</section>

## Challenge Seed
<section id='challengeSeed'>

<div id='js-seed'>

```js
const testArr = [
  'Given$a$text$file$of$many$lines',
  'where$fields$within$a$line$',
  'are$delineated$by$a$single$"dollar"$character',
  'write$a$program',
  'that$aligns$each$column$of$fields$',
  'by$ensuring$that$words$in$each$',
  'column$are$separated$by$at$least$one$space.',
  'Further,$allow$for$each$word$in$a$column$to$be$either$left$',
  'justified,$right$justified',
  'or$center$justified$within$its$column.'
];

function formatText (input, justification) {
  // Good luck!
}
```

</div>


### After Test
<div id='js-teardown'>

```js
console.info('after the test');
```

</div>

</section>

## Solution
<section id='solution'>


```js
const testArr = [
  'Given$a$text$file$of$many$lines',
  'where$fields$within$a$line$',
  'are$delineated$by$a$single$"dollar"$character',
  'write$a$program',
  'that$aligns$each$column$of$fields$',
  'by$ensuring$that$words$in$each$',
  'column$are$separated$by$at$least$one$space.',
  'Further,$allow$for$each$word$in$a$column$to$be$either$left$',
  'justified,$right$justified',
  'or$center$justified$within$its$column.'
];

String.prototype.repeat = function (n) { return new Array(1 + parseInt(n)).join(this); };

function formatText (input, justification) {
  let x, y, max, cols = 0, diff, left, right;
  for (x = 0; x < input.length; x++) {
    input[x] = input[x].split('$');
    if (input[x].length > cols) {
      cols = input[x].length;
    }
  }
  for (x = 0; x < cols; x++) {
    max = 0;
    for (y = 0; y < input.length; y++) {
      if (input[y][x] && max < input[y][x].length) {
        max = input[y][x].length;
      }
    }
    for (y = 0; y < input.length; y++) {
      if (input[y][x]) {
        diff = (max - input[y][x].length) / 2;
        left = ' '.repeat(Math.floor(diff));
        right = ' '.repeat(Math.ceil(diff));
        if (justification === 'left') {
          right += left; left = '';
        }
        if (justification === 'right') {
          left += right; right = '';
        }
        input[y][x] = left + input[y][x] + right;
      }
    }
  }
  for (x = 0; x < input.length; x++) {
    input[x] = input[x].join(' ');
  }
  input = input.join('\n');
  return input;
}

```

</section>