Object.entries

let obj = {
	key1: "value1",
	key2: "value2",
	key3: "value3",
	key4: "value4",
}
Object.entries(obj).forEach(([key, value]) => {
	console.log(key, value);
});

const object1 = {
  a: 'somestring',
  b: 42
};

for (let [key, value] of Object.entries(object1)) {
  console.log(`${key}: ${value}`);
}

// expected output:
// "a: somestring"
// "b: 42"
// order is not guaranteed

Object.entries(obj).forEach(([key, value]) => {
	console.log(key, value);
});

const object1 = {
  a: 'somestring',
  b: 42
};

for (let [key, value] of Object.entries(object1)) {
  console.log(`${key}: ${value}`);
}

// expected output:
// "a: somestring"
// "b: 42"
// order is not guaranteed

// Object Entries returns object as Array of [key,value] Array
const object1 = {
  a: 'somestring',
  b: 42
}
Object.entries(object1) // Array(2) [["a", "something"], ["b", 42]]
  .forEach(([key, value]) => console.log(`${key}: ${value}`))
// "a: somestring"
// "b: 42"

const arr = [ ['0', 'a'], ['1', 'b'], ['2', 'c'] ];
const obj = Object.fromEntries(arr);
console.log(obj); // { 0: "a", 1: "b", 2: "c" }

const object1 = {
  a: 'some string',
  b: 42
};

for (let [key, value] of Object.entries(object1)) {
  console.log(`${key}: ${value}`);
}

// expected output:
// "a: some string"
// "b: 42"
// order is not guaranteed

var buttons = {
  foo: 'bar',
  fiz: 'buz'
};

for ( var property in buttons ) {
  console.log( property ); // Outputs: foo, fiz or fiz, foo
}

const objectMap = (obj, fn) =>
  Object.fromEntries(
    Object.entries(obj).map(
      ([k, v], i) => [k, fn(v, k, i)]
    )
  )
  
const myObject = { a: 1, b: 2, c: 3 }

console.log(objectMap(myObject, v => 2 * v));