var person={
first_name:"johnny",
last_name: "johnson",
phone:"703-3424-1111"
};
for (var property in person) {
console.log(property,":",person[property]);
}let obj = {
key1: "value1",
key2: "value2",
key3: "value3"
}
Object.keys(obj).forEach(key => {
let value = obj[key];
//use key and value here
});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);
}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
});
// Sum up a particular property, and calculate its average
const myArray = [{x:100}, {x:200}, {x:300}];
const sum = myArray.map(element => element.x).reduce((a, b) => a + b, 0);
console.log(sum); // 600 = 0 + 100 + 200 + 300
const average = sum / myArray.length;
console.log(average); // 200