Remove All Falsy Values from an Array

easy

Last Updated - 26/08/2024

Problem Statement Solution 1: Using filter Method Solution 2: Using for Loop Solution 3: Using forEach Method Solution 4: Using reduce Method Solution 5: Using while Loop Solution 6: Using map and filter Solution 7: Using some Method Solution 8: Using Array.from with a Filter More Problems Solutions

Problem Statement

Write a function to remove all falsy values from an array. In JavaScript, falsy values are values that are considered false when encountered in a Boolean context. These values include false, 0, "" (empty string), null, undefined, and NaN.

Example 1

Input: array = [0, "Hello", false, 42, "", NaN, true, null, "World"]

Output: ["Hello", 42, true, "World"]

Solution 1: Using filter Method

function removeFalsyValuesFilter(arr) {
  return arr.filter(Boolean);
} 

const array1 =  [0, "Hello", false, 42, "", NaN, true, null, "World"];
removeFalsyValuesFilter(array1);  //output: ["Hello", 42, true, "World"]

Solution 2: Using for Loop

function removeFalsyValuesForLoop(arr) {
  const result = [];
  for (const value of arr) {
    if (value) {
      result.push(value);
    }
  }
  return result;
} 

const array1 =  [0, "Hello", false, 42, "", NaN, true, null, "World"];
removeFalsyValuesForLoop(array1);  //output: ["Hello", 42, true, "World"]

Solution 3: Using forEach Method

function removeFalsyValuesForEach(arr) {
  const result = [];
  arr.forEach(value => {
    if (value) {
      result.push(value);
    }
  });
  return result;
} 

const array1 =  [0, "Hello", false, 42, "", NaN, true, null, "World"];
removeFalsyValuesForEach(array1);  //output: ["Hello", 42, true, "World"]

Solution 4: Using reduce Method

function removeFalsyValuesReduce(arr) {
  return arr.reduce((acc, value) => {
    if (value) {
      acc.push(value);
    }
    return acc;
  }, []);
} 

const array1 =  [0, "Hello", false, 42, "", NaN, true, null, "World"];
removeFalsyValuesReduce(array1);  //output: ["Hello", 42, true, "World"]

Solution 5: Using while Loop

function removeFalsyValuesWhileLoop(arr) {
  const result = [];
  let index = 0;
  while (index < arr.length) {
    if (arr[index]) {
      result.push(arr[index]);
    }
    index++;
  }
  return result;
} 

const array1 =  [0, "Hello", false, 42, "", NaN, true, null, "World"];
removeFalsyValuesWhileLoop(array1);  //output: ["Hello", 42, true, "World"]

Solution 6: Using map and filter

function removeFalsyValuesMapFilter(arr) {
  return arr.map(value => value).filter(Boolean);
} 

const array1 =  [0, "Hello", false, 42, "", NaN, true, null, "World"];
removeFalsyValuesMapFilter(array1);  //output: ["Hello", 42, true, "World"]

Solution 7: Using some Method

function removeFalsyValuesSome(arr) {
  const result = [];
  arr.some(value => {
    if (value) {
      result.push(value);
    }
    return false; // Continue checking all values
  });
  return result;
} 

const array1 =  [0, "Hello", false, 42, "", NaN, true, null, "World"];
removeFalsyValuesSome(array1);  //output: ["Hello", 42, true, "World"]

Solution 8: Using Array.from with a Filter

function removeFalsyValuesArrayFrom(arr) {
  return Array.from(arr).filter(Boolean);
} 

const array1 =  [0, "Hello", false, 42, "", NaN, true, null, "World"];
removeFalsyValuesArrayFrom(array1);  //output: ["Hello", 42, true, "World"]