key name?

[indieisaconcept]

Is it possible to retrieve a key name as opposed to a value?

e.g

FROM:

"resources": [{
    "params": {
        "one": "optional",
        "two": "optional",
        "three": "optional"
    }
}, {
    "params": {
        "four": "optional",
        "five": "optional",
        "six": "optional"
    }
}]

TO:

[
    "one",
    "two",
    "three",
    "four",
    "five",
    "six"
]