How would you code in JavaScript to sort an error list without using the default sorting method?

This question is about writing a custom sorting function in JavaScript to sort an error list. Here the interviewer is trying to assess your knowledge about sorting algorithms and how you can implement them in JavaScript. The challenge here is to solve the problem without using the built-in sort() method of the JavaScript Array object.

There are several key points to consider when answering this question:

• Understand the data type of errors. Are they strings, numbers, objects with a date for instance?
• You would need to decide on an appropriate sorting algorithm based on your understanding of the error list; quicksort and mergesort are common choices. Remember that the choice of sorting algorithm can significantly impact the efficiency of your code.
• Write concise and clean code, also focus on explaining why you chose that particular sorting algorithm.

One way to sort an error list of numbers is by using a Bubble Sort algorithm. Here's how:

function bubbleSort(arr) {
    let len = arr.length;
    for (let i = 0; i < len; i++) {
        for (let j = 0; j < len-i-1; j++) {
            if (arr[j] > arr[j + 1]) { 
                // Swap numbers
                let tmp = arr[j];
                arr[j] = arr[j + 1];
                arr[j + 1] = tmp;
            }
        }
    }
    return arr;
}

var errorList = [4, 5, 6, 1, 2, 3];
console.log(bubbleSort(errorList)); // Sorted: 1,2,3,4,5,6 

Bubble Sort is simple but not the most efficient algorithm for larger data sets. It's great for a demonstration or when the data set is relatively small.

Another, more efficient way would be by implementing the Quick Sort algorithm. Here's how:

function quickSort(arr) {
    if (arr.length <= 1) {
        return arr;
    }

    let pivot = arr[arr.length - 1];
    let left = [];
    let right = [];

    for (let i = 0; i < arr.length - 1; i++) {
        if (arr[i] < pivot) {
            left.push(arr[i]);
        } else {
            right.push(arr[i]);
        }
    }

    return [...quickSort(left), pivot, ...quickSort(right)];
}

var errorList = [4, 5, 6, 1, 2, 3];
console.log(quickSort(errorList)); // Sorted: 1,2,3,4,5,6 

The Quick Sort algorithm is generally considered the fastest of the sorting algorithms for large data sets, and it performs well in real-world testing. It's a Divide and Conquer algorithm. It picks an element as pivot and partitions the given array around the picked pivot.