Sorting strings with decimal points in JavaScript

Suppose, we have an array of strings like this −

const arr = [ '.0', '.1', '.2', '.4', '.2.1', '.3', '.4.1', '.5', '.5.1.5' ];

We are required to write a JavaScript function that takes in one such array. Our function should simply sort the array in increasing order (as seen by a layman).

This means that strings with '.0', followed by '.1's, followed by '.2's, and so on. Therefore, after being sorted, the array should look like −

const output = [ '.0', '.1', '.2.1', '.2, '.3', '.4', '.4.1', '.5', '.5.1.5' ];

Example

The code for this will be −

const arr = [ '.0', '.1', '.2', '.4', '.2.1', '.3', '.4.1', '.5', '.5.1.5' ];
const compare = (a, b) => {
   if (a === b) {
      return 0
   };
   const aArr = a.split("."), bArr = b.split(".");
   for (let i = 0; i < Math.min(aArr.length, bArr.length); i++) {
      if (parseInt(aArr[i]) < parseInt(bArr[i])) {
         return -1
      };
      if (parseInt(aArr[i]) > parseInt(bArr[i])) {
         return 1
      };
   }
   if (aArr.length < bArr.length) {
      return -1
   };
   if (aArr.length > bArr.length) {
      return 1
   };
   return 0;
};
arr.sort(compare);
console.log(arr);

Output

And the output in the console will be −

[
   '.0', '.1',
   '.2', '.2.1',
   '.3', '.4',
   '.4.1', '.5',
   '.5.1.5'
]

AmitDiwan

Published on 25-Nov-2020 11:21:12