how to filter object code example

Example 1: how to filter object in javascript

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

Example 2: js filter object

/** filter object by key or value */

/** filter object function */
function filterObj( obj, predicate ) {
	var result = {}, key;

	for ( key in obj ) {
		if ( obj.hasOwnProperty( key ) && predicate( key, obj[ key ] ) ) {
			result[ key ] = obj[ key ];
		}
	}

	return result;
};

// example

// set object
var obj = {
	name : 'john',
	lastName : 'smith',
	age : 32
}

// filter out parameters using key and value
var filteredObj = filterObj( obj, function( key, value ) {
	return key !== 'age' && value !== 'smith'
});

// show result
console.log( filteredObj ); // { name: "john" }

Example 3: can filter be used on objects in javascript

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”} ]