To map and filter an array in JavaScript, we can use the filter() and map() methods together. To demonstrate this functionality, let’s write a function that returns all even numbers from an array, each doubled.
function getDoubledEvens(numbers) {
return numbers
.filter(num => num % 2 === 0) // Step 1: Keep only even numbers
.map(num => num * 2); // Step 2: Double them
}
// Example usage:
const nums = [1, 2, 3, 4, 5, 6];
const result = getDoubledEvens(nums);
console.log(result); // Output: [4, 8, 12]
What happens if the array is empty?
Answer: []
Can we apply this to an array of objects?
Answer: Yes
Is the original array modified?
Answer: No
Can this be rewritten using for loops?
Answer: Yes
Does the order of map() and filter() matter?
Answer: Yes