JavaScript program to print even numbers in an array

Given an array of numbers and the task is to write a JavaScript program to print all even numbers in that array. We will use the following methods to find even numbers in an array:

• Using for Loop
• Using while Loop
• Using forEach Loop
• Using filter Method
• Using for…of Loop

Example:

Input:    numbers_array1= [4, 76, 89, 61, 72, 64]
Output: [4,76,72,64]
Input:   numbers_array2= [15, 60, 90, 14, 7, 45]
Output: [60,90,14]

Method 1: Using for Loop

Approach: 

• Iterate each element in the array using for loop to check if (num %2==0), the condition to check even or not. 
• If the condition is satisfied then push the num into the even list. 
• After iterating all elements in an array print the even list.

Even numbers in an array are: 10,12

Method 2: Using while Loop

Approach: 

• Iterate through the array using the while loop.
• Check elements if (element%2==0) condition satisfies, we push the element into an even array. 
• After iterating all elements using a while loop, we print an even numbers array.

Even numbers in an array are: 44,26,48,64

Method 3: Using forEach Loop

Approach:

• Declare an array called “numbers” containing a set of integers.
• Declare an empty array called “even”.
• Use the forEach method to iterate through each element in the “numbers” array.
• Within the forEach loop, use an if statement to check if the current element is even using the modulus operator (element%2==0).
• If the element is even, use the push method to add it to the “even” array.
• After the forEach loop, use console.log () to display the message “Even numbers in an array are: [even numbers]” where [even numbers] is the array of even numbers.

This approach allows one to iterate through the entire array, check each element for even-ness, and add even numbers to a separate array, which is then displayed in the console.

Even numbers in an array are: 86,90,24

Method 4: Using filter Method

Approach:

• Declare an array called “numbers” containing a set of integers.
• Use the filter() method on the “numbers” array, passing in a callback function as the argument.
• The callback function should take in the current element as a parameter and use the modulus operator (element%2==0) to check if it is even.
• Return true for even numbers and false for odd numbers in the callback function.
• Assign the returned result of the filter method to a variable, let’s say ‘evenNumbers’.
• After the filter method, use console.log() to display the message “Even numbers in an array are: [evenNumbers]” where [evenNumbers] is the array of even numbers returned from the filter method.

The filter method returns a new array with all elements that pass the test implemented by the callback function.

Even numbers in an array are: 86,90,24

Method 5: Using for…of Loop

The for…of loop iterates over the iterable objects (like Array, Map, Set, arguments object, …,etc), invoking a custom iteration hook with statements to be executed for the value of each distinct property.

Example:

[ 2, 4, 6, 8 ]