public/subjects/no-adults-wanted

No Adults Wanted

filter

In JS most of the time, a loop is not needed and specials array methods can help doing the heavy work.

The first one we are going to see is the filter array method:

let values = [1, 23, 3, 43, 78, 9, 23, 12]

let isOver20 = (value) => {
  if (value > 20) {
    return true
  }
}

let valuesUnder10 = values.filter(isOver20)

console.log(valuesUnder10) // [23, 43, 78, 23]

In this case, values is an array and the .filter method is used to filter only those that are over 20.

This is achieved by giving filter a special function that will return true if we want to keep this value or not.

Filtering is the best way to remove elements from an array, when you only need to do a selection but not modify them.

Instructions

Create a function childrenOnly that takes an array of numbers and returns only those that are lower than 18

Example:

const result = childrenOnly([12, 11, 23, 44, 10])

console.log(result) // [12, 11, 10]