# How to find matching items in an array using JavaScript

By Atta Ur Rehman Shah (https://attacomsian.com/about). Published May 10, 2020. Topics: JavaScript.
Canonical URL: https://attacomsian.com/blog/javascript-array-find-matching-items

> A quick guide to learn how to find all matching items in an array by using vanilla JavaScript.

Last week, we looked at [JavaScript arrays](https://attacomsian.com/blog/javascript-arrays) in detail and how to use them to store multiple values in a single variable. Today, you'll learn a useful trick to find all matching items in an array by using the `Array.filter()` method.

The `Array.filter()` method creates a new array by iterating over all elements of an array and returns those that pass a certain condition as an array.

The callback function passed as an argument takes in up to three optional parameters. The first is the current element in the iteration, the second is the index of the current item in the array, and the third is the array itself.

In the callback body, you can test if the current item matches what you're looking for, and return a boolean (`true` or `false`) accordingly.

Here is an example:

```javascript
const values = [15, 45, 22, 19, 55, 62, 78];

// find all values > 25
const greaterThan25 = values.filter(item => {
    return item > 25;
});

// find all values < 25
const lessThan25 = values.filter(item => item < 25);

console.log(greaterThan25);
// [45, 55, 62, 78]

console.log(lessThan25);
// [15, 22, 19]
```

The `Array.filter()` method is not just limited to primitive arrays. You can even use it to **filter an array of objects** as shown in the following example:

```javascript
const users = [
    {
        name: 'John Deo',
        age: 35
    },
    {
        name: 'Emma Kel',
        age: 24
    }
    ,
    {
        name: 'Kristy Adam',
        age: 42
    }
];

// find all users older than 40 years
const filteredUsers = users.filter(user => {
    return user.age >= 40;
});

console.log(filteredUsers);
// [{ name: 'Kristy Adam', age: 42 }]
```

The `Array.filter()` filter works in all modern browsers, and Internet Explorer 9 and above. However, you can use a [polyfill](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter#Polyfill) to support IE6 and higher.

Take a look at [this guide](https://attacomsian.com/blog/javascript-arrays) to learn more about JavaScript arrays and their methods.