javascript filter array of objects

1let arr=[{id:1,title:'A', status:true}, {id:3,title:'B',status:true}, {id:2, title:'xys', status:true}];
2//find where title=B
3let x = arr.filter((a)=>{if(a.title=='B'){return a}});
4console.log(x)//[{id:3,title:'B',status:true}]

1// use filter() function. Let say we have array of object.
2let arr = [
3  {name: "John", age: 30},
4  {name: "Grin", age: 10},
5  {name: "Marie", age: 50},
6];
7//Now I want an array in which person having age more than 40 is not
8//there, i.e, I want to filter it out using age property. So
9let newArr = arr.filter((person)=>(return person.age <= 40));
10//filter function expects a function if it return true then it added 
11//into new array, otherwise it is ignored. So new Array would be
12/* [
13	{name: "John", age: 30},
14  	{name: "Grin", age: 10},
15   ]
16*/

1const data = [
2  {
3    name: 'Bob',
4    gender: 'male',
5    age: 34,
6  },
7  {
8    name: 'Carol',
9    gender: 'female',
10    age: 36,
11  },
12  {
13    name: 'Ted',
14    gender: 'male',
15    age: 38,
16  },
17  {
18    name: 'Alice',
19    gender: 'female',
20    age: 40,
21  },
22];
23
24const arr1 = data.filter(d => d.age > 37);
25console.log('arr1', arr1);
26
27const arr2 = data.filter(d => d.gender === 'female');
28console.log('arr2', arr2);
29
30const ageAndGender = d => d.age > 37 && d.gender === 'female';
31
32const arr3 = data.filter(ageAndGender);
33console.log('arr3', arr3);
34

1var heroes = [
2	{name: “Batman”, franchise: “DC”},
3	{name: “Ironman”, franchise: “Marvel”},
4	{name: “Thor”, franchise: “Marvel”},
5	{name: “Superman”, franchise: “DC”}
6];
7
8var marvelHeroes =  heroes.filter(function(hero) {
9	return hero.franchise == “Marvel”;
10});
11
12// [ {name: “Ironman”, franchise: “Marvel”}, {name: “Thor”, franchise: “Marvel”} ]

1let people = [
2  { name: "Steve", age: 27, country: "America" },
3  { name: "Jacob", age: 24, country: "America" }
4];
5
6let filteredPeople = people.filter(function (currentElement) {
7  // the current value is an object, so you can check on its properties
8  return currentElement.country === "America" && currentElement.age < 25;
9});
10
11console.log(filteredPeople);
12// [{ name: "Jacob", age: 24, country: "America" }]
13

1function isBigEnough(value) {
2  return value >= 10
3}
4
5let filtered = [12, 5, 8, 130, 44].filter(isBigEnough)
6// filtered is [12, 130, 44]
7