How to sort an array by numbers in strings?-CodePudding

I have an array:

[
  'B3', 'B4', 'B5',
 
  'B6', 'C3', 'C4',
 
  'C5', 'C6', 'D3',
 
  'D4', 'D5', 'D6'
]

I need to sort it by the number in each string (in ascending order). The number can be one/double-digit/triple-digit.

Here's what the final array should look like:

[
  'B3', 'C3', 'D3',
 
  'B4', 'C4', 'D4',
 
  'B5', 'C5', 'D5',
 
  'B6', 'C6', 'D6'
]

How can I do it?

CodePudding user response：

Assuming that there will always be only one letter at the beginning - then here is the solution:

const input = [
    'B3', 'B4', 'B5',
    'B6', 'C3', 'C4',
    'C5', 'C645', 'D3',
    'D4', 'D532', 'D6'
];

console.log(sort(input));

function sort(array) {
   return array.sort((a, b) => {
       const aVal = parseInt(a.slice(1), 10);
       const bVal = parseInt(b.slice(1), 10);

       if (aVal < bVal) {
           return -1;
       }
       if (aVal > bVal) {
           return 1;
       }

       return 0;
   });
}

CodePudding user response：

You can have a look to the sort method: https://www.w3schools.com/jsref/jsref_sort.asp

And how you can pass a function in for values comparison as a criteria to sort the elements :)

const myArray = [
  'B3', 'B4', 'B5',
 
  'B6', 'C3', 'C4',
 
  'C5', 'C6', 'D3',
 
  'D4', 'D5', 'D6'
]

const sortedArray = myArray.sort((a, b) => a[1] - b[1])
console.log(sortedArray)

CodePudding user response：

You can use sort method of array with custom comparator function as:

const arr = [
  'B3', 'B4', 'B5',
  'B6', 'C3', 'C4',
  'C5', 'C6', 'D3',
  'D4', 'D5', 'D6',
];

const result = arr.sort((a, b) =>  a.match(/\d /) -  b.match(/\d /));
console.log(result);

/* This is not a part of answer. It is just to give the output full height. So IGNORE IT */
.as-console-wrapper { max-height: 100% !important; top: 0; }

CodePudding user response：

let data = [
  'B3', 'B4', 'B5',
 
  'B6', 'C3', 'C4',
 
  'C5', 'C6', 'D3',
 
  'D4', 'D5', 'D6'
];

console.log(data.map(x => [x.match(/[A-Z]/g)[0], parseInt(x.match(/\d /g))]).sort((a, b) => {
    return a[1] - b[1] || a[0].localeCompare(b[0]);
}).map(x => x[0]   x[1]))

CodePudding user response：

Here is what I came up with:

const sortByNum = arr => {
    let newArr = arr.map(item => {
        return {
            letter: item[0],
            number: item.substr(1, item.length),
        };
    });
    newArr.sort((numA, numB) => numA.number - numB.number);
    return newArr.map(item => {
        return (item.letter   item.number);
    });
};

its basically dividing each string into key/value pairs, sorting them by number, then joining them back into strings.