why we use filter in js code example

Example 1: filter javascript array

var words = ['spray', 'limit', 'elite', 'exuberant', 'destruction', 'present'];

const result = words.filter(word => word.length > 6);

console.log(result);

Example 2: javascript filter

const filtered = array.filter(item => {
    return item < 20;
});
// An example that will loop through an array
// and create a new array containing only items that
// are less than 20. If array is [13, 65, 101, 19],
// the returned array in filtered will be [13, 19]