10 Genius Hacks Using Array.filter() That You Must Try

Array filtering in JavaScript is a powerful feature that can be used creatively and practically.

Here are some innovative uses of the array.filter method:

1. Removing Duplicates

const numbers = [1, 2, 2, 3, 4, 4, 5];
const uniqueNumbers = numbers.filter((value, index, self) => self.indexOf(value) === index);
// uniqueNumbers: [1, 2, 3, 4, 5]

2. Finding Prime Numbers

const numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
const isPrime = num => {
    for (let i = 2, s = Math.sqrt(num); i <= s; i++)
        if (num % i === 0) return false;
    return num > 1;
};
const primeNumbers = numbers.filter(isPrime);
// primeNumbers: [2, 3, 5, 7]

3. Filtering Objects by Property

const users = [
    { name: 'Alice', age: 25 },
    { name: 'Bob', age: 30 },
    { name: 'Charlie', age: 25 }
];
const age25 = users.filter(user => user.age === 25);
// age25: [{ name: 'Alice', age: 25 }, { name: 'Charlie', age: 25 }]

4. Excluding Falsy Values

const values = [0, 1, false, 2, '', 3, null, undefined, 4];
const truthyValues = values.filter(Boolean);
// truthyValues: [1, 2, 3, 4]