filter object array javascript code example

Example 1: how to filter an array of objects in javascript

let arr=[{id:1,title:'A', status:true}, {id:3,title:'B',status:true}, {id:2, title:'xys', status:true}];
//find where title=B
let x = arr.filter((a)=>{if(a.title=='B'){return a}});
console.log(x)//[{id:3,title:'B',status:true}]

Example 2: js filter array of objects by value

var heroes = [
	{name: “Batman”, franchise: “DC”},
	{name: “Ironman”, franchise: “Marvel”},
	{name: “Thor”, franchise: “Marvel”},
	{name: “Superman”, franchise: “DC”}
];

var marvelHeroes =  heroes.filter(function(hero) {
	return hero.franchise == “Marvel”;
});

// [ {name: “Ironman”, franchise: “Marvel”}, {name: “Thor”, franchise: “Marvel”} ]

Example 3: filtering json array in javascript

const data = [
  {
    name: 'Bob',
    gender: 'male',
    age: 34,
  },
  {
    name: 'Carol',
    gender: 'female',
    age: 36,
  },
  {
    name: 'Ted',
    gender: 'male',
    age: 38,
  },
  {
    name: 'Alice',
    gender: 'female',
    age: 40,
  },
];

const arr1 = data.filter(d => d.age > 37);
console.log('arr1', arr1);

const arr2 = data.filter(d => d.gender === 'female');
console.log('arr2', arr2);

const ageAndGender = d => d.age > 37 && d.gender === 'female';

const arr3 = data.filter(ageAndGender);
console.log('arr3', arr3);

Example 4: javascript filter array of objects

let people = [
  { name: "Steve", age: 27, country: "America" },
  { name: "Jacob", age: 24, country: "America" }
];

let filteredPeople = people.filter(function (currentElement) {
  // the current value is an object, so you can check on its properties
  return currentElement.country === "America" && currentElement.age < 25;
});

console.log(filteredPeople);
// [{ name: "Jacob", age: 24, country: "America" }]

Example 5: javascript filter array of objects by array

var arr = [1,2,3,4],
    brr = [2,4],
    res = arr.filter(f => !brr.includes(f));
console.log(res);

Example 6: javascript object filter

function objectFilter = (obj, predicate) => 
    Object.keys(obj)
          .filter( key => predicate(obj[key]) )
          .reduce( (res, key) => (res[key] = obj[key], res), {} );

// Example use:
var scores = {
    John: 2, Sarah: 3, Janet: 1
};

var filtered = objectFilter(scores, num => num > 1); 
console.log(filtered);