Check if array keys are numbers

Question

I have array with keys that could be either real strings

var array = {
    'Blue' : 1,
    'Red'  : 2,
    'Green': 3
}

or it could be numbers but sometimes floats considered as strings, I guess because it's not an array but an object:

var array = {
    9     : 1,
    '9.5' : 2,
    10    : 3
    '10.5': 4
}

This one is not really an array so I need to sort it if explicitly if I want to keep the original order:

$.each(Object.keys(array).sort(function(a, b) {
    var anum = parseFloat(a),
        bnum = parseFloat(b);
    return anum - bnum;
}), function(index, value) {
    ……
});

if I don't do that, my array is:

var array = {
    9     : 1,
    10    : 3,
    '9.5' : 2
    '10.5': 4
}

I need to keep it sorted. My solution is working well but I need to check if the keys are numbers or string. If they are string, I don't need to sort the array. Something like:

$.each(/*if my array has numbers as keys I sort the array as above, else just loop*/,
function(index, value) {
    ……
});

You cannot. [Here is the reason and discussion](http://stackoverflow.com/questions/3633362/is-there-anyway-to-use-a-numeric-type-as-an-object-key) — Vishal Kumar Sahu, Feb 14 '17 at 21:09
@ibrahimmahrir That is exactly why he is sorting the keys before iterating over them. — blex, Feb 14 '17 at 21:15
Maybe use try catch. You can put the code inside a try block, then parseInt inside. If it is not parseable the catch block will execute. Make sure to put a parameter on the catch statement to hold the error, then you can just ignore it. — Abana Clara, Feb 15 '17 at 00:27

score 6 · Accepted Answer · answered Feb 14 '17 at 21:09

6

Really shouldn't call that object 'array', but:

if(Object.keys(array).every(key => !isNaN(key)){ //sort }

answered Feb 14 '17 at 21:09

chrispy

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Check if array keys are numbers

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