array-filter-2

/**
 * We have an array of values, some of them are falsy, some not. 
 * 
 * We will use filter function to return only truthy ones.
 */ 
let arr = [1, 2, 3, true, false, 'a', 'b', 'c', undefined, null, '', NaN, 4, 5, 6]

let r = arr.filter(Boolean)

console.log(r)
//Output: [1, 2, 3, true, "a", "b", "c", 4, 5, 6]