Map multiple properties in array of objects to the same array JavaScript

Suppose, we have an array of objects like this −

const arr = [
   {a: 1, b: 2},
   {a: 3, b: 4},
   {a: 5, b: 6}
];

We are required to write a JavaScript function that takes in one such array of objects. The function should then map this array to an array of Number literals like this −

const output = [1, 2, 3, 4, 5, 6];

Example

const arr = [
   {a: 1, b: 2},
   {a: 3, b: 4},
   {a: 5, b: 6}
];
const pushToArray = (arr = []) => {
   const result = arr.reduce((acc, obj) => {
    acc.push(obj.a);
   acc.push(obj.b);
   return acc;
}, []);
   return result;
};
console.log(pushToArray(arr));

Output

And the output in the console will be −

[ 1, 2, 3, 4, 5, 6 ]