filter an array of objects in 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: filter array object by its elements

const things = {
  thing: [
    { place: 'here', name: 'stuff' },
    { place: 'there', name: 'morestuff1' },
    { place: 'there', name: 'morestuff2' }, 
  ],
};

const removeDuplicates = (array, key) => {
  return array.reduce((arr, item) => {
    const removed = arr.filter(i => i[key] !== item[key]);
    return [...removed, item];
  }, []);
};

console.log(removeDuplicates(things.thing, 'place'));
// > [{ place: 'here', name: 'stuff' }, { place: 'there', name: 'morestuff2' }]

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: how the filter() function works javascript

const arr = [1, 2, 3, 4, 5, 6, 7, 8, 9];

const filter = arr.filter((number) => number > 5);
console.log(filter); // [6, 7, 8, 9]

Example 6: 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);