How to sort 2 dimensional array by column value?

Question

Can any one help me sort a 2 dimensional Array in JavaScript?

It will have data in the following format:

[12, AAA]
[58, BBB]
[28, CCC]
[18, DDD]

It should look like this when sorted:

[12, AAA]
[18, DDD]
[28, CCC]
[58, BBB]

So basically, sorting by the first column.

Cheers

Answer 1

It's this simple:

var a = [[12, 'AAA'], [58, 'BBB'], [28, 'CCC'],[18, 'DDD']];

a.sort(sortFunction);

function sortFunction(a, b) {
    if (a[0] === b[0]) {
        return 0;
    }
    else {
        return (a[0] < b[0]) ? -1 : 1;
    }
}

I invite you to read the documentation.

If you want to sort by the second column, you can do this:

a.sort(compareSecondColumn);

function compareSecondColumn(a, b) {
    if (a[1] === b[1]) {
        return 0;
    }
    else {
        return (a[1] < b[1]) ? -1 : 1;
    }
}

Answer 2

The best approach would be to use the following, as there may be repetitive values in the first column.

var arr = [[12, 'AAA'], [12, 'BBB'], [12, 'CCC'],[28, 'DDD'], [18, 'CCC'],[12, 'DDD'],[18, 'CCC'],[28, 'DDD'],[28, 'DDD'],[58, 'BBB'],[68, 'BBB'],[78, 'BBB']];

arr.sort(function(a,b) {
    return a[0]-b[0]
});

Answer 3

Try this:

//WITH FIRST COLUMN
arr = arr.sort((a, b) => a[0] - b[0]);

//WITH SECOND COLUMN
arr = arr.sort((a, b) => a[1] - b[1]);

Note: Original answer used a greater than (>) instead of minus (-) which is what the comments are referring to as incorrect.

Answer 4

Using the arrow function, and sorting by the second string field

var a = [[12, 'CCC'], [58, 'AAA'], [57, 'DDD'], [28, 'CCC'],[18, 'BBB']];
a.sort((a, b) => a[1].localeCompare(b[1]));
console.log(a)

Answer 5

If you're anything like me, you won't want to go through changing each index every time you want to change the column you're sorting by.

function sortByColumn(a, colIndex){

    a.sort(sortFunction);

    function sortFunction(a, b) {
        if (a[colIndex] === b[colIndex]) {
            return 0;
        }
        else {
            return (a[colIndex] < b[colIndex]) ? -1 : 1;
        }
    }

    return a;
}

var sorted_a = sortByColumn(a, 2);

Answer 6

in one line:

var cars = [
  {type:"Volvo", year:2016},
  {type:"Saab", year:2001},
  {type:"BMW", year:2010}
]


function myFunction() {
  return cars.sort((a, b)=> a.year - b.year)
}

Answer 7

If you want to sort based on first column (which contains number value), then try this:

arr.sort(function(a,b){
  return a[0]-b[0]
})

If you want to sort based on second column (which contains string value), then try this:

arr.sort(function(a,b){
  return a[1].charCodeAt(0)-b[1].charCodeAt(0)
})

P.S. for the second case, you need to compare between their ASCII values.

Answer 8

Nothing special, just saving the cost it takes to return a value at certain index from an array.

function sortByCol(arr, colIndex){
    arr.sort(sortFunction)
    function sortFunction(a, b) {
        a = a[colIndex]
        b = b[colIndex]
        return (a === b) ? 0 : (a < b) ? -1 : 1
    }
}
// Usage
var a = [[12, 'AAA'], [58, 'BBB'], [28, 'CCC'],[18, 'DDD']]
sortByCol(a, 0)
console.log(JSON.stringify(a))
// "[[12,"AAA"],[18,"DDD"],[28,"CCC"],[58,"BBB"]]"

Answer 9

I use sort to sort the array

This is my code :

const sortArr = (arr) => {
    arr.sort((valA, valB) => valA[0] - valB[0])
    return arr
}

const arr = [
    [12, 'AAA'],
    [58, 'BBB'],
    [28, 'CCC'],
    [18, 'DDD']
]
console.log(sortArr(arr))

Answer 10

Standing on the shoulders of charles-clayton and @vikas-gautam, I added the string test which is needed if a column has strings as in OP.

return isNaN(a-b) ? (a === b) ? 0 : (a < b) ? -1 : 1 : a-b  ;

The test isNaN(a-b) determines if the strings cannot be coerced to numbers. If they can then the a-b test is valid.

Note that sorting a column of mixed types will always give an entertaining result as the strict equality test (a === b) will always return false. See MDN here

This is the full script with Logger test - using Google Apps Script.

function testSort(){

function sortByCol(arr, colIndex){
    arr.sort(sortFunction);
    function sortFunction(a, b) {
        a = a[colIndex];
        b = b[colIndex];
       return isNaN(a-b) ? (a === b) ? 0 : (a < b) ? -1 : 1 : a-b  ;  // test if text string - ie cannot be coerced to numbers.
       // Note that sorting a column of mixed types will always give an entertaining result as the strict equality test will always return false
       // see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Equality_comparisons_and_sameness

       }
}
// Usage
var a = [ [12,'12', 'AAA'],
          [12,'11', 'AAB'],
          [58,'120', 'CCC'],
          [28,'08', 'BBB'],
          [18,'80', 'DDD'],
        ]
    var arr1 = a.map(function (i){return i;}).sort();  // use map to ensure tests are not corrupted by a sort in-place.

    Logger.log("Original unsorted:\n     " + JSON.stringify(a));
    Logger.log("Vanilla sort:\n     " + JSON.stringify(arr1));
    sortByCol(a, 0);
    Logger.log("By col 0:\n     " + JSON.stringify(a));
    sortByCol(a, 1);
    Logger.log("By col 1:\n     " + JSON.stringify(a));
    sortByCol(a, 2);
    Logger.log("By col 2:\n     " + JSON.stringify(a));

/* vanilla sort returns " [
                            [12,"11","AAB"],
                            [12,"12","AAA"],
                            [18,"80","DDD"],
                            [28,"08","BBB"],
                            [58,"120","CCC"]
                          ]
   if col 0 then returns "[
                            [12,'12',"AAA"],
                            [12,'11', 'AAB'],
                            [18,'80',"DDD"],
                            [28,'08',"BBB"],
                            [58,'120',"CCC"]
                          ]"
   if col 1 then returns "[
                            [28,'08',"BBB"],
                            [12,'11', 'AAB'],
                            [12,'12',"AAA"],
                            [18,'80',"DDD"],
                            [58,'120',"CCC"],

                          ]"
   if col 2 then returns "[
                            [12,'12',"AAA"],
                            [12,'11', 'AAB'],
                            [28,'08',"BBB"],
                            [58,'120',"CCC"],
                            [18,'80',"DDD"],
                          ]"
*/

}

Answer 11

Solution vary depend on column value is numeric or string. 

To sort by first column if value is numeric,
array.sort( (a, b) => a[0] - b[0]);

To sort by second column if value is numeric,
array.sort( (a, b) => a[1] - b[1]);

To sort by first column if value is string/letter,
array.sort( function(a, b) {
    const nameA = a[0].toUpperCase(); // to avoid case while sort
    const nameB = b[0].toUpperCase();
    if(nameA > nameB)
        return 1;
    else if(nameB > nameA)
        return -1;
    else
        return 0;     
})

Answer 12

As my usecase involves dozens of columns, I expanded @jahroy's answer a bit. (also just realized @charles-clayton had the same idea.)
I pass the parameter I want to sort by, and the sort function is redefined with the desired index for the comparison to take place on.

var ID_COLUMN=0
var URL_COLUMN=1

findings.sort(compareByColumnIndex(URL_COLUMN))

function compareByColumnIndex(index) {
  return function(a,b){
    if (a[index] === b[index]) {
        return 0;
    }
    else {
        return (a[index] < b[index]) ? -1 : 1;
    }
  }
}

Answer 13

Good idea Sabbir Ahmed, but only order by the first character, for three:

array.sort((a, b) => (a[n].charCodeAt(0)*1000000 + a[n].charCodeAt(1)*1000 + a[n].charCodeAt(2)) - (b[n].charCodeAt(0)*1000000 + b[n].charCodeAt(1)*1000 + b[n].charCodeAt(2)));

Answer 14

Sorting two dimensional array specifying the sort order and column. Default order 0 means no change hence order must be specified: 1 => Ascending, -1 => descending. Default column is 0.

let sort2d = (arr2d = [], order = 0, column = 0) => {
    if (column < 0 || column > 1) {
        if (order == 1) 
            return arr2d.sort((a, b) => a[column] - b[column])
        if (order == -1) 
            return arr2d.sort((a, b) => b[column] - a[column])
    }
    return arr2d
}

let arr2d = [ [5, 3], [2, 5], [9, 1], [4, 1] ]
console.log(sort2d(arr2d, 1, -1)) //  [ [ 2, 5 ], [ 5, 3 ], [ 9, 1 ], [ 4, 1 ] ]

Answer 15

If you want a solution to sort multi-dimensional integer array where sub-array have a fixed length [ [ -6, 1, 5 ], [ -8, 3, 5 ], [ -8, 2, 6 ], [ -8, 3, 6 ] ]

const array = [ [ -6, 1, 5 ], [ -8, 3, 5 ], [ -8, 2, 6 ], [ -8, 3, 6 ] ]
const multiArraySort = (array, num) => {
  return array = array.sort((a,b) => {
    let boolean = true
    let i = 0 
    while(boolean){      
      if(a[i] === b[i]){        
        if(a[i+1] === b[i+1]){          
          i < num - 1 ? i++ : boolean = false
        }else {          
          return a[i+1] - b[i+1]          
        }        
      } else {                
        return a[i] - b[i]
      }
    }
    return 0
  })
}
// 3 represents the fixed length of sub-array
let sarray = multiArraySort(array, 3) //cant' assign in const array

Answer: [ [ -8, 2, 6 ], [ -8, 3, 5 ], [ -8, 3, 6 ], [ -6, 1, 5 ] ]