Retrieving a property of a JSON object by index?

Question

Assuming this JSON object:

var obj = {
    \"set1\": [1, 2, 3],
    \"set2\": [4, 5, 6, 7, 8],
    \"set3\": [9, 10, 11, 12]
};

The \"set

Answer 1

You could iterate over the object and assign properties to indexes, like this:

var lookup = [];
var i = 0;

for (var name in obj) {
    if (obj.hasOwnProperty(name)) {
        lookup[i] = obj[name];
        i++;
    }
}

lookup[2] ...

However, as the others have said, the keys are in principle unordered. If you have code which depends on the corder, consider it a hack. Make sure you have unit tests so that you will know when it breaks.