freeCodeCamp/guide/english/certifications/javascript-algorithms-and-data-structures/basic-javascript/generate-random-whole-numbers-within-a-range/index.md

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title: Generate Random Whole Numbers within a Range
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# Generate Random Whole Numbers within a Range


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## Hints

### Hint 1
`randomRange` should use both `myMax` and `myMin`, and return a random number in your range.

You cannot pass the test if you are only re-using the function `ourRandomRange` inside your `randomRange` formula. You need to write your own formula that uses the variables `myMax` and `myMin`. It will do the same job as using `ourRandomRange`, but ensures that you have understood the principles of the `Math.floor()` and `Math.random()` functions.



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## Solutions

<details><summary>Solution 1 (Click to Show/Hide)</summary>

```javascript
function randomRange(myMin, myMax) {
  return Math.floor(Math.random() * (myMax - myMin + 1) + myMin);
}
```

#### Code Explanation
- `Math.random()` generates our random number between 0 and ≈ 0.9.
- Before multiplying it, it resolves the part between parenthesis `(myMax - myMin + 1)` because of the grouping operator `(   )`.
- The result of that multiplication is followed by adding `myMin` and then "rounded" to the largest integer less than or equal to it (eg: 9.9 would result in 9)

If the values were `myMin = 1, myMax= 10`, one result could be the following:
 1. `Math.random() = 0.8244326990411024`
 2. `(myMax - myMin + 1) = 10 - 1 + 1 -> 10`
 3. `a * b =  8.244326990411024`
 4. `c + myMin = 9.244326990411024`
 5. `Math.floor(9.244326990411024) = 9`


#### Relevant Links

- ["Math.random()" - *MDN JavaScript reference*](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/random)
- ["Math.floor()" - *MDN JavaScript reference*](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/floor)
- ["Grouping operator" - *MDN JavaScript reference*](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Grouping)

</details>