Merge Sort in Javascript

Published on 28 April 2022 (Updated: 25 September 2022)

Merge Sort in Javascript

Welcome to the Merge Sort in Javascript page! Here, you'll find the source code for this program as well as a description of how the program works.

Current Solution

function mergeSort (unsortedArray) {
  if (unsortedArray.length <= 1) {
    return unsortedArray;
  }
  const middle = Math.floor(unsortedArray.length / 2);
  const left = unsortedArray.slice(0, middle);
  const right = unsortedArray.slice(middle);
  return merge(
    mergeSort(left), mergeSort(right)
  );
}

function merge (left, right) {
  let resultArray = [], leftIndex = 0, rightIndex = 0;
  while (leftIndex < left.length && rightIndex < right.length) {
    if (left[leftIndex] < right[rightIndex]) {
      resultArray.push(left[leftIndex]);
      leftIndex++;
    } else {
      resultArray.push(right[rightIndex]);
      rightIndex++;
    }
  }
  return resultArray
          .concat(left.slice(leftIndex))
          .concat(right.slice(rightIndex));
}

const main = (input) => {
    const inputValidation = /^"?(\d+,\s*){2,}\d+(,"?|"?)$/gm;
    if (inputValidation.test(input) == true) {
        let arr;
        arr = input.replace(/(\s|"|'|`)/g, '');
        arr = arr.split(',');
        arr = arr.map(function (n) {
            return parseInt(n, 10);
        });
        arr = arr.filter(n => n);
        arr=mergeSort(arr);
        console.log(arr);
    }
    else {
        console.log(usage);
    }
}

const usage = `Usage: please provide a list of at least two integers to sort in the format "1, 2, 3, 4, 5"`;

if (process.argv.length > 2) {
    const input = process.argv[2];
    main(input);
}
else {
    console.log(usage);
}

Merge Sort in Javascript was written by:

If you see anything you'd like to change or update, please consider contributing.

How to Implement the Solution

No 'How to Implement the Solution' section available. Please consider contributing.

How to Run the Solution

No 'How to Run the Solution' section available. Please consider contributing.