2634. Filter Elements from Array.js

// 2634. Filter Elements from Array
// Easy
// Companies
// Hint
// Given an integer array arr and a filtering function fn, return a filtered array filteredArr.

// The fn function takes one or two arguments:

// arr[i] - number from the arr
// i - index of arr[i]
// filteredArr should only contain the elements from the arr for which the expression fn(arr[i], i) evaluates to a truthy value. A truthy value is a value where Boolean(value) returns true.

// Please solve it without the built-in Array.filter method.

 

// Example 1:

// Input: arr = [0,10,20,30], fn = function greaterThan10(n) { return n > 10; }
// Output: [20,30]
// Explanation:
// const newArray = filter(arr, fn); // [20, 30]
// The function filters out values that are not greater than 10
// Example 2:

// Input: arr = [1,2,3], fn = function firstIndex(n, i) { return i === 0; }
// Output: [1]
// Explanation:
// fn can also accept the index of each element
// In this case, the function removes elements not at index 0
// Example 3:

// Input: arr = [-2,-1,0,1,2], fn = function plusOne(n) { return n + 1 }
// Output: [-2,0,1,2]
// Explanation:
// Falsey values such as 0 should be filtered out
 

// Constraints:

// 0 <= arr.length <= 1000
// -109 <= arr[i] <= 109

/**
 * @param {number[]} arr
 * @param {Function} fn
 * @return {number[]}
 */
var filter = function(arr, fn) {
    let filteredArr = [];
    for(let i=0; i<arr.length; i++){
        if (fn(arr[i],i)){
            filteredArr.push(arr[i]);
        };
    };
    return filteredArr;
};

//no hints, second try