My object is:
[ '4e95b308d36f429729000021': 1,
'4e95b309d36f429729000039': 2,
'4e95b308d36f429729000001': 1 ]
I want to sort so that the 2 valued key is first. I know this question has been asked a million times before, but this doesn't work:
var descSort;
descSort = function(a, b) {
return b.value - a.value;
};
popularLocationsArray.sort(descSort);
First of all your code is not a valid JavaScript, it should be:
var popularLocationsArray = [
{'4e95b308d36f429729000021': 1},
{'4e95b309d36f429729000039': 2},
{'4e95b308d36f429729000001': 1}
]
Knowing that your problem is that you don't know the key name in each object and you want to sort by this key's value. First you need to define a helper function:
function anyVal(obj) {
for(var key in obj) {
if(obj.hasOwnProperty(key)) {
return obj[key]
}
}
}
Now sorting is simple:
popularLocationsArray.sort(function(a,b) {return anyVal(a) - anyVal(b)});
You can't sort an object. An object has no reason to return it's key in any particular order.
Now if you meant something like this, you have options:
function descSort(a, b) {
var value1 = +a[Object.keys(a)[0]],
value2 = +b[Object.keys(b)[0]];
return value2 - value1;
}
[ {'4e95b308d36f429729000021': 1},
{'4e95b309d36f429729000039': 2},
{'4e95b308d36f429729000001': 1} ].sort(descSort)
This uses Object.keys, which doesn't have native
Just to make life interesting, you can make the objects in the array sortable (that is, within a containing array) by creating your own custom object:
function Foo(key, value) {
this[key] = value;
}
Foo.prototype.toString = function() {
for (var p in this) {
if (this.hasOwnProperty(p)) {
return this[p];
}
}
}
var a = new Foo('4e95b308d36f429729000021', 1);
var b = new Foo('4e95b309d36f429729000039', 2);
var c = new Foo('4e95b308d36f429729000001', 1);
var popularLocationsArray = [a, b, c];
alert(popularLocationsArray); // 1, 2, 1
alert(popularLocationsArray.sort()); //1, 1, 2
Or you could make it sort on the key name, or combine the key and property, whatever. Just have the toString method return whatever you want them sorted on.
{...}instead of[...].