Where do I belong? No. Seriously! [solved]

JavaScript
1

my code should work. and it does.
except on the last test.
which is weird.
for some reason (unicode blah blah) the .sort thinks 10 is less than 2.
but it’s even weirder because it doesn’t think 15 is greater than 10 or 5 or 2, but it knows that 19 is greater than 10 and 2 in the earlier test.

Your code so far

function getIndexToIns(arr, num)
{
    var result = 0;
    var count = 0;
    var newArr = arr.sort();
    for (i = 0; i < newArr.length; i++)
    {
        if (num > newArr[i])
        {
            count++;
        }
        else
        {
            result = count;
        }
    }
    console.log("arr = " + arr + " | newArr = " + newArr);  
  return result;
}

console.log(getIndexToIns([10, 20, 30, 40, 50], 35));
//should return 3.
console.log(getIndexToIns([10, 20, 30, 40, 50], 30));
//should return 2.
console.log(getIndexToIns([40, 60], 50));
//should return 1.
console.log(getIndexToIns([3, 10, 5], 3));
//should return 0.
console.log(getIndexToIns([5, 3, 20, 3], 5));
//should return 2.
console.log(getIndexToIns([2, 20, 10], 19));
//should return 2.
console.log(getIndexToIns([2, 5, 10], 15));
//should return 3.

Link to the challenge:
https://www.freecodecamp.org/challenges/where-do-i-belong

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bad%20count1246×464 77 KB

2

In your example, 10 is less than 2 w/r/t sort, by default it’s going to sort lexicographically, like in a dictionary

3

so do i need to int.parse?
also what is w/r/t?

4

Sorry, With Respect To.

And nope, you don’t need to parse anything, you just need to give sort a callback function. You always need to do this if you’re sorting numbers: to be honest the only time you don’t is if you want an array of things to be sorted in the order of the character codes for their string representation (0-9, then A-Z, then a-z etc).

If you look at the examples on MDN, there are a few numeric ones https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/sort; return a - b in the callback, anyway I think, I always end up checking anyway, it never sticks in my head.

Default sort is pretty useless, is the main thing you should take away. It has to be - the are a variety of ways people need to sort things and a variety of things they want sorting, so that’s what the callback’s for; along the lines of arr.sort((a,b) => a - b) or whatever

1 Like
5

thanks. this led me down a path. where i replaced
var newArr = arr.sort();
with
var newArr = arr.sort(function(a, b) {return a-b});

and now the numbers sort properly.

but i’m still getting the same result on the last test.

6 
function getIndexToIns(arr, num)
{
    var result = 0;
    var count = 0;
    var newArr = arr.sort(function(a, b) {return a-b});
    for (i = 0; i < newArr.length; i++)
    {
        if (num > newArr[i])
        {
            count++;
        }
        result = count;
    }
  return result;
}

console.log(getIndexToIns([10, 20, 30, 40, 50], 35));
//should return 3.
console.log(getIndexToIns([10, 20, 30, 40, 50], 30));
//should return 2.
console.log(getIndexToIns([40, 60], 50));
//should return 1.
console.log(getIndexToIns([3, 10, 5], 3));
//should return 0.
console.log(getIndexToIns([5, 3, 20, 3], 5));
//should return 2.
console.log(getIndexToIns([2, 20, 10], 19));
//should return 2.
console.log(getIndexToIns([2, 5, 10], 15));
//should return 3.

figured it out

my else {} was unnecessary.