how create aarray of object inside array of object wiyth loop in javascript code example

Example 1: javascript loop through object example

var person={
 	first_name:"johnny",
  	last_name: "johnson",
	phone:"703-3424-1111"
};
for (var property in person) {
  	console.log(property,":",person[property]);
}

Example 2: loop array of objects

const myArray = [{x:100}, {x:200}, {x:300}];

const newArray= myArray.map(element => {
    return {
        ...element,
        x: element.x * 2
    };
});

console.log(myArray); // [100, 200, 300]
console.log(newArray); // [200, 400, 600]