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id	title	challengeType	videoUrl	forumTopicId	dashedName
cf1111c1c12feddfaeb1bdef	Generate Random Whole Numbers with JavaScript	1	https://scrimba.com/c/cRn6bfr	18186	generate-random-whole-numbers-with-javascript

--description--

It's great that we can generate random decimal numbers, but it's even more useful if we use it to generate random whole numbers.

Use Math.random() to generate a random decimal.
Multiply that random decimal by 20.
Use another function, Math.floor() to round the number down to its nearest whole number.

Remember that Math.random() can never quite return a 1 and, because we're rounding down, it's impossible to actually get 20. This technique will give us a whole number between 0 and 19.

Putting everything together, this is what our code looks like:

Math.floor(Math.random() * 20);

We are calling Math.random(), multiplying the result by 20, then passing the value to Math.floor() function to round the value down to the nearest whole number.

--instructions--

Use this technique to generate and return a random whole number between 0 and 9.

--hints--

The result of randomWholeNum should be a whole number.

assert(
  typeof randomWholeNum() === 'number' &&
    (function () {
      var r = randomWholeNum();
      return Math.floor(r) === r;
    })()
);

You should use Math.random to generate a random number.

assert(code.match(/Math.random/g).length >= 1);

You should have multiplied the result of Math.random by 10 to make it a number that is between zero and nine.

assert(
  code.match(/\s*?Math.random\s*?\(\s*?\)\s*?\*\s*?10[\D]\s*?/g) ||
    code.match(/\s*?10\s*?\*\s*?Math.random\s*?\(\s*?\)\s*?/g)
);

You should use Math.floor to remove the decimal part of the number.

assert(code.match(/Math.floor/g).length >= 1);

--seed--

--after-user-code--

(function(){return randomWholeNum();})();

--seed-contents--

function randomWholeNum() {

  // Only change code below this line

  return Math.random();
}

--solutions--

function randomWholeNum() {
  return Math.floor(Math.random() * 10);
}

2.2 KiB Raw Blame History