javascript sort array by multiple properties

1homes.sort(
2   function(a, b) {          
3      if (a.city === b.city) {
4         // Price is only important when cities are the same
5         return b.price - a.price;
6      }
7      return a.city > b.city ? 1 : -1;
8   });

1array.sort(function(a,b){
2  let i = 0, result = 0;
3  while(i < sortBy.length && result === 0) {
4    result = sortBy[i].direction*(a[ sortBy[i].prop ].toString() < b[ sortBy[i].prop ].toString() ? -1 : (a[ sortBy[i].prop ].toString() > b[ sortBy[i].prop ].toString() ? 1 : 0));
5    i++;
6  }
7  return result;
8})
9

1var sort_by;
2
3(function() {
4    // utility functions
5    var default_cmp = function(a, b) {
6            if (a == b) return 0;
7            return a < b ? -1 : 1;
8        },
9        getCmpFunc = function(primer, reverse) {
10            var dfc = default_cmp, // closer in scope
11                cmp = default_cmp;
12            if (primer) {
13                cmp = function(a, b) {
14                    return dfc(primer(a), primer(b));
15                };
16            }
17            if (reverse) {
18                return function(a, b) {
19                    return -1 * cmp(a, b);
20                };
21            }
22            return cmp;
23        };
24
25    // actual implementation
26    sort_by = function() {
27        var fields = [],
28            n_fields = arguments.length,
29            field, name, reverse, cmp;
30
31        // preprocess sorting options
32        for (var i = 0; i < n_fields; i++) {
33            field = arguments[i];
34            if (typeof field === 'string') {
35                name = field;
36                cmp = default_cmp;
37            }
38            else {
39                name = field.name;
40                cmp = getCmpFunc(field.primer, field.reverse);
41            }
42            fields.push({
43                name: name,
44                cmp: cmp
45            });
46        }
47
48        // final comparison function
49        return function(A, B) {
50            var a, b, name, result;
51            for (var i = 0; i < n_fields; i++) {
52                result = 0;
53                field = fields[i];
54                name = field.name;
55
56                result = field.cmp(A[name], B[name]);
57                if (result !== 0) break;
58            }
59            return result;
60        }
61    }
62}());
63