javascript object loop

                                    // object to loop through
let obj = { first: "John", last: "Doe" };

// loop through object and log each key and value pair
//ECMAScript 5
Object.keys(obj).forEach(function(key) {
    console.log(key, obj[key]);
});

//ECMAScript 6
for (const key of Object.keys(obj)) {
    console.log(key, obj[key]);
}

//ECMAScript 8
Object.entries(obj).forEach(
    ([key, value]) => console.log(key, value)
);

// OUTPUT
/*
   first John
   last Doe
*/

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

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

// for-of with Object.keys()
for (var key of Object.keys(p)) {
    console.log(key + " -> " + p[key])
}

// Object.entries()
for (let [key, value] of Object.entries(p)) {
  console.log(`${key}: ${value}`);
}

                                    const object = { a: 1, b: 2, c: 3 };

for (const property in object) {
  console.log(`${property}: ${object[property]}`);
}

// expected output:
// "a: 1"
// "b: 2"
// "c: 3"

                                    var obj = { first: "John", last: "Doe" };

Object.keys(obj).forEach(function(key) {
    console.log(key, obj[key]);
});

                                    let obj = {
  key1: "value1",
  key2: "value2",
  key3: "value3"
}

Object.keys(obj).forEach(key => {
    console.log(key, obj[key]);
});
// key1 value1
// key2 value2
// key3 value3

// using for in - same output as above
for (let key in obj) {
  let value = obj[key];
  console.log(key, value);
}