traverse only one key in an object javascript code example

Example 1: loop object stack

var p = {
    "p1": "value1",
    "p2": "value2",
    "p3": "value3"
};

for (var key in p) {
    if (p.hasOwnProperty(key)) {
        console.log(key + " -> " + p[key]);
    }
}

Example 2: going through every attributes of an object javascript

let a = {x: 200, y: 1}
let attributes = Object.keys(a)
console.log(attributes)
//output: ["x", "y"]