Greatest Value in an object

I am making a game with obstacles at different x and y coordinates and I am put all the obstacles into a list like so:

var list = [{x:200, y:400},{x:120, y:400},{x:170, y:400}];

I am trying to find the object with the greatest x value.
Is there some kind of max() function for objects like these? So I can find the max object?
Max X: 200
Also please do forgive my if my questions are sloppy and have some errors, I am still a child at age 12 and do not find these errors often.

>Solution :

Firstly, what you showed is not a proper object in JavaScript. I guess the proper list you want to present is like below?

var list = [
  { x: 200, y: 400 },
  { x: 120, y: 400 },
  { x: 170, y: 400 }
]

Then, if you want to get the max value, try this:

function getMaxValue(list, key) {
    const keyArray = list.map(l => l[key])
    return Math.max(keyArray)
}

By using above function, if you want to find the max x, try getMaxValue(list, 'x'). If you want to find the max y, try getMaxValue(list, 'y')