filter()

.filter() creates a new array that keeps only the elements that pass a test.

Use it when you want to remove items from an array without changing the original array.

Example

const numbers = [1, 2, 3, 4, 5, 6, 7]
const evenNumbers = numbers.filter(isEven)
 
function isEven(element) {
  return element % 2 === 0
}
 
console.log(evenNumbers) // [2, 4, 6]

Another Example

const ages = [16, 17, 18, 19, 20, 60]
const adults = ages.filter((age) => age >= 18)
 
console.log(adults) // [18, 19, 20, 60]