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# Where do I Belong - JavaScript Solution & Walkthrough

## (14/16) Learn how to solve coding challenges using FreeCodeCamp's curriculum.

Benjamin Semah
·Apr 14, 2022·

• 14/16 Where do I Belong
• Understanding the Challenge
• Pseudocode
• Solving the Challenge
• Final Solution
• Congratulations!

## 14/16 Where do I Belong

Return the lowest index at which a value (second argument) should be inserted into an array (first argument) once it has been sorted. The returned value should be a number.

For example, `getIndexToIns([1,2,3,4], 1.5)` should return `1` because it is greater than `1` (index 0), but less than `2` (index 1).

Likewise, `getIndexToIns([20,3,5], 19)` should return `2` because once the array has been sorted it will look like `[3,5,20]` and `19` is less than `20` (index 2) and greater than `5` (index 1).

``````function getIndexToIns(arr, num) {

return num;
}

getIndexToIns([40, 60], 50);
``````

Credit: FreeCodeCamp.org

## Understanding the Challenge

For this challenge, you are to complete the `getIndexToIn` function. This function takes an array `arr` as first argument and a number `num` as second argument.

Your task is to find the lowest possible index `num` at which num can be insert into the array when it has been sorted. We are provided with 2 examples in the problem description.

## Pseudocode

``````Given an array and an index number
Update the array by inserting the number into the arry
Sort the updated array
Find the index of the number in the sorted array
return the index of the number.
``````

## Solving the Challenge

First, we need to update the `arr` by adding `num` to it. To add an element to an array, we can use the `.push()` method. This will add the number to the end of the array.

``````arr.push(num)
console.log(arr) // [ 40, 60, 50 ]
``````

In the given example, the initial array is [40, 60]. Using the `.push()` method adds `num` which is 50 to the end of the array.

Next, we sort the array. We are not told specifically in challenge description how the sorting is to be done. However, looking at test cases provided, all of them were sorted in ascending order. Thus, its safe to assume that the function should do the sorting in ascending order. We can use the `.sort()` method to sort the array as follows;

``````arr.sort((a, b) => a - b)
console.log(arr) // [40, 50, 60]
``````

We can now use the `indexOf()` method to find the index of `num`. We'll save the results in a variable. Let's call the variable `indexOfNum`.

``````const indexOfNum = arr.indexOf(num)
console.log(indexOfNum) // 1
``````

Finally we return `indexOfNum`. Our function is now complete.

``````return index(indexOfNum)
``````

## Final Solution

``````function getIndexToIns(arr, num) {
arr.push(num)
arr.sort((a, b) => a - b)
const indexOfNum = arr.indexOf(num)
return indexOfNum;
}

getIndexToIns([40, 60], 50); // 1
``````

## Congratulations!

You just cracked the 14th challenge in this series.

Cheers and happy coding!