Retool filter array

1. Does .filter return an array?
2. How do you apply an array filter?
3. Does .filter mutate array?

Does .filter return an array?

The filter() method creates a new array filled with elements that pass a test provided by a function. The filter() method does not execute the function for empty elements. The filter() method does not change the original array.

How do you apply an array filter?

Using filter() on an Array of Numbers

var newArray = array. filter(function(item) return condition; ); The item argument is a reference to the current element in the array as filter() checks it against the condition . This is useful for accessing properties, in the case of objects.

Does .filter mutate array?

The filter() method is a copying method. It does not alter this but instead returns a shallow copy that contains the same elements as the ones from the original array (with some filtered out). However, the function provided as callbackFn can mutate the array.