javascript - sorting object by keys (strings as numbers) -

i have data set in object, keys strings

 { '17': '17-17:30',    '20': '20:00-21',    '21': '21-22',    '22': '22-23',     '23': '23-24',    '01': '1-2',    '02': '2-3',    '03': '3-4',    '04': '4-5',    '05': '5-6',    '06': '6-7',   '07': '7-7:30',   '08': '08:50-9' } 

i want arrange them numerically 01 comes first , 23 comes last.

here's code i'm using:

    var sort_object = function(map) {     var keys = _.sortby(_.keys(map), function(a) { return number(a); });     var newmap = {};     _.each(keys, function(k) {     newmap[k] = map[k];      });      return newmap;     } 

it still returns 17 in beginning. did go wrong?

as blender pointed out, objects not ordered. need use array. there several ways set array, , once have data in array it's easy sort it.

here couple of examples. first, let's try making array of arrays. outer array list of elements, , each element of array array of 2 elements, key , value.

so paste code favorite javascript console, such 1 in chrome:

var data = [     [ '17', '17-17:30' ],     [ '20', '20:00-21' ],     [ '21', '21-22' ],     [ '22', '22-23' ],     [ '23', '23-24' ],     [ '01', '1-2' ],     [ '02', '2-3' ],     [ '03', '3-4' ],     [ '04', '4-5' ],     [ '05', '5-6' ],     [ '06', '6-7' ],     [ '07', '7-7:30' ],     [ '08', '08:50-9' ] ];  var result = data.slice().sort( function( a, b ) {     return +a[0] - +b[0]; });  json.stringify( result, null, 4 ); 

it log:

[     [         "01",         "1-2"     ],     [         "02",         "2-3"     ],     [         "03",         "3-4"     ],     [         "04",         "4-5"     ],     [         "05",         "5-6"     ],     [         "06",         "6-7"     ],     [         "07",         "7-7:30"     ],     [         "08",         "08:50-9"     ],     [         "17",         "17-17:30"     ],     [         "20",         "20:00-21"     ],     [         "21",         "21-22"     ],     [         "22",         "22-23"     ],     [         "23",         "23-24"     ] 

or, instead of array of arrays, can use array of objects. more convenient work with. paste code javascript console:

var data = [     { key: '17', value: '17-17:30' },     { key: '20', value: '20:00-21' },     { key: '21', value: '21-22' },     { key: '22', value: '22-23' },     { key: '23', value: '23-24' },     { key: '01', value: '1-2' },     { key: '02', value: '2-3' },     { key: '03', value: '3-4' },     { key: '04', value: '4-5' },     { key: '05', value: '5-6' },     { key: '06', value: '6-7' },     { key: '07', value: '7-7:30' },     { key: '08', value: '08:50-9'} ];  var result = data.slice().sort( function( a, b ) {     return +a.key - +b.key; });  json.stringify( result, null, 4 ); 

it log:

[     {         "key": "01",         "value": "1-2"     },     {         "key": "02",         "value": "2-3"     },     {         "key": "03",         "value": "3-4"     },     {         "key": "04",         "value": "4-5"     },     {         "key": "05",         "value": "5-6"     },     {         "key": "06",         "value": "6-7"     },     {         "key": "07",         "value": "7-7:30"     },     {         "key": "08",         "value": "08:50-9"     },     {         "key": "17",         "value": "17-17:30"     },     {         "key": "20",         "value": "20:00-21"     },     {         "key": "21",         "value": "21-22"     },     {         "key": "22",         "value": "22-23"     },     {         "key": "23",         "value": "23-24"     } ] 

either way, can see, once have data in suitable format (i.e. data whole needs array), becomes simple sort it.

let's @ sort function in more detail (using second example):

var result = data.slice().sort( function( a, b ) {     return +a.key - +b.key; }); 

in code a.key gets value key property of 1 of array elements. + in front of converts string number - using number function simpler way it. +b.key. , subtracting 2 numbers gives correct sort function return: positive, negative, or 0 value depending on whether a.key or b.key greater of 2 or if they're equal.

the first example works similarly, using +a[0] - +b[0] instead of +a.key - +b.key.

the .slice() call in each example makes copy of array. omit if want sort original array.