loop through object of arrays 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 object array iteration

let obj = {
  key1: "value1",
  key2: "value2",
  key3: "value3"
}

Object.keys(obj).forEach(key => {
  let value = obj[key];
  //use key and value here
});

Example 4: how to loop through an array of objects+

var arr = [[1,2], [3,4], [5,6]];
 for (var i=0; i < arr.length; i++) {
  for (var j=0; j < arr[i].length; j++) {
    console.log(arr[i][j]);
  }
}

Example 5: iterate over array of objects javascript

// Retrieve a subset of an array based on particular criteria

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

const newArray = myArray.filter(element => element.x > 250);
console.log(newArray); // [{x:300}]