javascript loop through object array

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

let arr = [object0, object1, object2];

for (let elm of arr) {
  console.log(elm);
}

var people=[
  {first_name:"john",last_name:"doe"},
  {first_name:"mary",last_name:"beth"}
];
for (let i = 0; i < people.length; i++) { 
  console.log(people[i].first_name);
}

var arr = [{id: 1},{id: 2},{id: 3}];

for (var elm of arr) {
  console.log(elm);
}

yourArray.forEach(function (arrayItem) {
    var x = arrayItem.prop1 + 2;
    console.log(x);
});

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

myArray.forEach((element, index, array) => {
    console.log(element.x); // 100, 200, 300
    console.log(index); // 0, 1, 2
    console.log(array); // same myArray object 3 times
});

var cars = [{name: 'Audi'}, {name: 'BMW'}, {name: 'Ferrari'}, {name: 'Mercedes'}, {name: 'Maserati'}];

for(var i = 0; i < cars.length; i++) {
    console.log(cars[i].name);
}

//Only to be used if you need the numbers
var array = new Array(item1,item2,item3)

for(i=0;i<array.length;i++){
  if(i==2){
    console.log(array[i])
  }
}