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# Count number of even and odd elements in an array

• Difficulty Level : Easy
• Last Updated : 13 Mar, 2023

For the given array of integers, count even and odd elements.

Examples:

```Input:
int arr[5] = {2, 3, 4, 5, 6}
Output:
Number of even elements = 3
Number of odd elements = 2

Input:
int arr[5] = {22, 32, 42, 52, 62}
Output:
Number of even elements = 5
Number of odd elements = 0```

Solution: We can also check if a number is odd or even

• By doing AND of 1 and that digit, if the result comes out to be 1 then the number is odd otherwise even.
• By its divisibility by 2. A number is said to be odd if it is not divisible by 2, otherwise its even.

Here, we will check if a number is odd, then we will increment the odd counter otherwise we will increment the even counter.

Below is the implementation of the above approach:

## C

 `// C program to count number of even ` `// and odd elements in an array ` `#include ` ` `  `void` `CountingEvenOdd(``int` `arr[], ``int` `arr_size) ` `{ ` `    ``int` `even_count = 0; ` `    ``int` `odd_count = 0; ` ` `  `    ``// loop to read all the values in the array ` `    ``for` `(``int` `i = 0; i < arr_size; i++) { ` ` `  `        ``// checking if a number is completely ` `        ``// divisible by 2 ` `        ``if` `(arr[i] & 1 == 1) ` `            ``odd_count++; ` `        ``else` `            ``even_count++; ` `    ``} ` ` `  `    ``printf``(``"Number of even elements = %d \nNumber of odd "` `           ``"elements = %d"``, ` `           ``even_count, odd_count); ` `} ` ` `  `// Driver Code ` `int` `main() ` `{ ` `    ``int` `arr[] = { 2, 3, 4, 5, 6 }; ` `    ``int` `n = ``sizeof``(arr) / ``sizeof``(arr[0]); ` ` `  `    ``// Function Call ` `    ``CountingEvenOdd(arr, n); ` `}`

## C++

 `// C++ program to count number of even ` `// and odd elements in an array ` `#include ` `using` `namespace` `std; ` ` `  `void` `CountingEvenOdd(``int` `arr[], ``int` `arr_size) ` `{ ` `    ``int` `even_count = 0; ` `    ``int` `odd_count = 0; ` ` `  `    ``// loop to read all the values in the array ` `    ``for` `(``int` `i = 0; i < arr_size; i++) { ` `         `  `          ``// checking if a number is completely ` `        ``// divisible by 2 ` `        ``if` `(arr[i] & 1 == 1) ` `            ``odd_count++; ` `        ``else` `            ``even_count++; ` `    ``} ` ` `  `    ``cout << ``"Number of even elements = "` `<< even_count ` `         ``<< ``"\nNumber of odd elements = "` `<< odd_count; ` `} ` ` `  `// Driver Code ` `int` `main() ` `{ ` `    ``int` `arr[] = { 2, 3, 4, 5, 6 }; ` `    ``int` `n = ``sizeof``(arr) / ``sizeof``(arr[0]); ` `       `  `      ``// Function Call ` `    ``CountingEvenOdd(arr, n); ` `}`

## Java

 `// JAVA program to count number of even ` `// and odd elements in an array ` `import` `java.io.*; ` ` `  `class` `GFG { ` ` `  `    ``static` `void` `CountingEvenOdd(``int` `arr[], ``int` `arr_size) ` `    ``{ ` `        ``int` `even_count = ``0``; ` `        ``int` `odd_count = ``0``; ` ` `  `        ``// loop to read all the values in ` `        ``// the array ` `        ``for` `(``int` `i = ``0``; i < arr_size; i++) { ` `             `  `              ``// checking if a number is ` `            ``// completely divisible by 2 ` `            ``if` `((arr[i] & ``1``) == ``1``) ` `                ``odd_count++; ` `            ``else` `                ``even_count++; ` `        ``} ` ` `  `        ``System.out.println(``"Number of even"` `                           ``+ ``" elements = "` `+ even_count ` `                           ``+ ``" Number of odd elements = "` `                           ``+ odd_count); ` `    ``} ` ` `  `    ``// Driver Code ` `    ``public` `static` `void` `main(String[] args) ` `    ``{ ` `        ``int` `arr[] = { ``2``, ``3``, ``4``, ``5``, ``6` `}; ` `        ``int` `n = arr.length; ` `           `  `          ``// Function Call ` `        ``CountingEvenOdd(arr, n); ` `    ``} ` `} ` ` `  `// This code is Contributed by anuj_67.`

## Python3

 `# Python3 program to count number of ` `# even and odd elements in an array ` ` `  ` `  `def` `CountingEvenOdd(arr, arr_size): ` `    ``even_count ``=` `0` `    ``odd_count ``=` `0` ` `  `    ``# loop to read all the values ` `    ``# in the array ` `    ``for` `i ``in` `range``(arr_size): ` ` `  `        ``# checking if a number is ` `        ``# completely divisible by 2 ` `        ``if` `(arr[i] & ``1` `=``=` `1``): ` `            ``odd_count ``+``=` `1` `        ``else``: ` `            ``even_count ``+``=` `1` ` `  `    ``print``(``"Number of even elements = "``, ` `          ``even_count) ` `    ``print``(``"Number of odd elements = "``, ` `          ``odd_count) ` ` `  ` `  `# Driver Code ` `arr ``=` `[``2``, ``3``, ``4``, ``5``, ``6``] ` `n ``=` `len``(arr) ` ` `  `# Function Call ` `CountingEvenOdd(arr, n) ` ` `  `# This code is contributed by sahishelangia `

## C#

 `// C# program to count number of even ` `// and odd elements in an array ` `using` `System; ` ` `  `class` `GFG { ` ` `  `    ``static` `void` `CountingEvenOdd(``int``[] arr, ``int` `arr_size) ` `    ``{ ` `        ``int` `even_count = 0; ` `        ``int` `odd_count = 0; ` ` `  `        ``// loop to read all the values in ` `        ``// the array ` `        ``for` `(``int` `i = 0; i < arr_size; i++) { ` `             `  `              ``// checking if a number is ` `            ``// completely divisible by 2 ` `            ``if` `((arr[i] & 1) == 1) ` `                ``odd_count++; ` `            ``else` `                ``even_count++; ` `        ``} ` ` `  `        ``Console.WriteLine(``"Number of even"` `                          ``+ ``" elements = "` `+ even_count ` `                          ``+ ``" Number of odd elements = "` `                          ``+ odd_count); ` `    ``} ` ` `  `    ``// Driver Code ` `    ``public` `static` `void` `Main() ` `    ``{ ` `        ``int``[] arr = { 2, 3, 4, 5, 6 }; ` `        ``int` `n = arr.Length; ` `       `  `          ``// Function Call ` `        ``CountingEvenOdd(arr, n); ` `    ``} ` `} ` ` `  `// This code is Contributed by anuj_67.`

## PHP

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## Javascript

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Output

```Number of even elements = 3
Number of odd elements = 2```

Time Complexity: O(n)

Auxiliary Space: O(1) because it is using constant space for variables

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