for loop array of objects 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: javascript loop through array of objects es6

/* new options with IE6: loop through array of objects */

const people = [
  {id: 100, name: 'Vikash'},
  {id: 101, name: 'Sugam'},
  {id: 102, name: 'Ashish'}
];

// using for of
for (let persone of people) {
  console.log(persone.id + ': ' + persone.name);
}

// using forEach(...)
people.forEach(person => {
 console.log(persone.id + ': ' + persone.name);
});
// output of above two methods
// 100: Vikash
// 101: Sugam
// 102: Ashish


// forEach(...) with index
people.forEach((person, index) => {
 console.log(index + ': ' + persone.name);
});
// output of above code in console
// 0: Vikash
// 1: Sugam
// 2: Ashish

Example 3: javascript loop through array of objects

let arr = [object0, object1, object2];

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

Example 4: js loop array of objects

// Array of objects
const p = [{
  "p1": "value1",
  "p2": "value2",
  "p3": "value3"
},
{
  "p4": "value4",
  "p5": "value5",
  "p6": "value6"
}];

// Get the objects out of the array
for (let obj of p) {
  // console.log(obj);
  // output: 
  // { p1: 'value1', p2: 'value2', p3: 'value3' }
  // { p4: 'value4', p5: 'value5', p6: 'value6' }
  // Now we can loop the objects in the array by nesting the 'for in' loop inside the 'for of' loop
  for(let key in obj) {
    console.log(key);
    // output:
    // p1
    // p2
    // p3
    // p4
    // p5
    // p6
    // console.log(obj[key]);
    // output
    // value1
    // value2
    // value3
    // value4
    // value5
    // value6
  }
}

Example 5: how to get value in array object value using for loop in javascript

const people = [ {name: "john", age:23},
                {name: "john", age:43},
                {name: "jim", age:101},
                {name: "bob", age:67} ];

const john = people.find(person => person.name === 'john');
console.log(john);

Example 6: how to get value in array object value using for loop in javascript

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