How can i find an Object key with the longest char length in an array of objects

Say i have a collection of objects like so

var collection = [
{
     name:"John",
     age:12,
     location:"Califonia",
     gender:"Male"
},
{
     name:"Jane",
     age:18,
     location:"New york",
     gender:"Female"
}
]

it is obvious "location" is the object key with the longest character length.

But how can i get this dynamically as i dont know how collection will be structured in advance.

if you are sure the items in the collection will always have the same structure you can simple do this.

var collection = [
{
     name:"John",
     age:12,
     location:"Califonia",
     gender:"Male"
},
{
     name:"Jane",
     age:18,
     location:"New york",
     gender:"Female"
}
]

function getMaxKeys(collection){
        var keys = Object.keys(collection[0]);
        var keyWithMaxWidth = keys.reduce(function(prev, current){
            if(prev.length > current.length) return prev;
            else return current
        });
        return keyWithMaxWidth;
}

getMaxKeys(collection) //location