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---
title: Align columns
id: 594810f028c0303b75339ad0
challengeType: 5
---
## Description
< section id = 'description' >
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Given a text file of many lines, where fields within a line are delineated by a single < code > $< / code > character, write a program that aligns each column of fields by ensuring that words in each column are separated by at least one space. Further, allow for each word in a column to be either left justified, right justified, or center justified within its column.
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< / section >
## Instructions
< section id = 'instructions' >
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Use the following text to test your programs:
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< pre >
Given$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 >
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< strong > Note that:< / strong >
< ul >
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< li > The example input texts lines may, or may not, have trailing dollar characters.< / li >
< li > All columns should share the same alignment.< / li >
< li > Consecutive space characters produced adjacent to the end of lines are insignificant for the purposes of the task.< / li >
< li > Output text will be viewed in a mono-spaced font on a plain text editor or basic terminal.< / li >
< li > The minimum space between columns should be computed from the text and not hard-coded.< / li >
< li > It is not a requirement to add separating characters between or around columns.< / li >
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< / ul >
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< / section >
## Tests
< section id = 'tests' >
```yml
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tests:
- text: < code > formatText</ code > is a function.
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testString: assert(typeof formatText === 'function', '< code > formatText< / code > is a function.');
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- text: '< code > formatText</ code > with the above input and "right" justification should produce the following: '
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testString: 'assert.strictEqual(formatText(testInput, ''right''), rightAligned, ''< code > formatText< / code > with the above input and "right" justification should produce the following: '');'
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- text: '< code > formatText</ code > with the above input and "left" justification should produce the following: '
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testString: 'assert.strictEqual(formatText(testInput, ''left''), leftAligned, ''< code > formatText< / code > with the above input and "left" justification should produce the following: '');'
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- text: '< code > formatText</ code > with the above input and "center" justification should produce the following: '
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testString: 'assert.strictEqual(formatText(testInput, ''center''), centerAligned, ''< code > formatText< / code > with the above input and "center" justification should produce the following: '');'
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```
< / 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.'
];
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function formatText(input, justification) {
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// Good luck!
}
```
< / div >
### After Test
< div id = 'js-teardown' >
```js
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const testInput = [
'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$column.'
];
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const rightAligned = ' Given a text file of many lines\n' +
' where fields within a line \n' +
' are delineated by a single "dollar" character\n' +
' write a program\n' +
' that aligns each column of fields \n' +
' by ensuring that words in each \n' +
' column are separated by at least one space.\n' +
' Further, allow for each word in a column to be either left \n' +
'justified, right justified\n' +
' or center justified within its column.';
const leftAligned = 'Given a text file of many lines \n' +
'where fields within a line \n' +
'are delineated by a single "dollar" character\n' +
'write a program \n' +
'that aligns each column of fields \n' +
'by ensuring that words in each \n' +
'column are separated by at least one space.\n' +
'Further, allow for each word in a column to be either left \n' +
'justified, right justified\n' +
'or center justified within its column. ';
const centerAligned = ' Given a text file of many lines \n' +
' where fields within a line \n' +
' are delineated by a single \"dollar\" character\n' +
' write a program \n' +
' that aligns each column of fields \n' +
' by ensuring that words in each \n' +
' column are separated by at least one space.\n' +
' Further, allow for each word in a column to be either left \n' +
'justified, right justified\n' +
' or center justified within its column. ';
```
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< / div >
< / section >
## Solution
< section id = 'solution' >
```js
const testArr = [
'Given$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); };
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function formatText(input, justification) {
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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') {
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right += left; left = '';
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}
if (justification === 'right') {
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left += right; right = '';
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}
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 >