freeCodeCamp

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title	id	challengeType	isHidden	forumTopicId
Word wrap	594810f028c0303b75339ad4	5	false	302344

Description

Even today, with proportional fonts and complex layouts, there are still cases where you need to wrap text at a specified column. The basic task is to wrap a paragraph of text in a simple way.

Instructions

Write a function that can wrap this text to any number of characters. As an example, the text wrapped to 80 characters should look like the following:

Wrap text using a more sophisticated algorithm such as the Knuth and Plass TeX
algorithm. If your language provides this, you get easy extra credit, but you
must reference documentation indicating that the algorithm is something better
than a simple minimum length algorithm.

Tests

tests:
  - text: wrap should be a function.
    testString: assert.equal(typeof wrap, 'function');
  - text: wrap should return a string.
    testString: assert.equal(typeof wrap('abc', 10), 'string');
  - text: wrap(80) should return 4 lines.
    testString: assert(wrapped80.split('\n').length === 4);
  - text: Your <code>wrap</code> function should return our expected text.
    testString: assert.equal(wrapped80.split('\n')[0], firstRow80);
  - text: wrap(42) should return 7 lines.
    testString: assert(wrapped42.split('\n').length === 7);
  - text: Your <code>wrap</code> function should return our expected text.
    testString: assert.equal(wrapped42.split('\n')[0], firstRow42);

Challenge Seed

function wrap(text, limit) {
  return text;
}

After Test

const text =
`Wrap text using a more sophisticated algorithm such as the Knuth and Plass TeX algorithm.
If your language provides this, you get easy extra credit,
but you ''must reference documentation'' indicating that the algorithm
is something better than a simple minimum length algorithm.`;

const wrapped80 = wrap(text, 80);
const wrapped42 = wrap(text, 42);

const firstRow80 =
    'Wrap text using a more sophisticated algorithm such as the Knuth and Plass TeX';

const firstRow42 = 'Wrap text using a more sophisticated';

Solution

function wrap(text, limit) {
  const noNewlines = text.replace('\n', '');
  if (noNewlines.length > limit) {
    // find the last space within limit
    const edge = noNewlines.slice(0, limit).lastIndexOf(' ');
    if (edge > 0) {
      const line = noNewlines.slice(0, edge);
      const remainder = noNewlines.slice(edge + 1);
      return line + '\n' + wrap(remainder, limit);
    }
  }
  return text;
}

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