# Generate an Array by multiplying each element of given Array by K

• Difficulty Level : Basic
• Last Updated : 19 Jan, 2022

Given an array arr[] of size N and an integer K. The task is to multiply each element of the array by K.

Examples :

Input: arr[] = { 3, 4 }, K = 2
Output: 6 8
Explanation: The elements become 3*2 = 6 and 4*2 = 8.

Input: arr[] = { 0, 1, 2 }, K = 7
Output: { 0, 7, 14 }

Approach: The given problem can be solved using the following steps :

• Iterate through all the elements in the list
• Multiply each element by K
• Returned the modified list

Below is the implementation of the above approach.

## C++

 `// C++ code for the above approach``#include ``using` `namespace` `std;` `// Function to multiply all``// the elements of array by K``void` `multiplyAllByK(vector<``int``> arr, ``int` `K)``{``    ``int` `N = arr.size();` `    ``// Loop to multiply all``    ``// the array elements``    ``for` `(``int` `i = 0; i < N; i++) {``        ``int` `x = arr[i];``        ``arr[i] = K * x;``    ``}` `    ``// Print the modified array``    ``for` `(``int` `i = 0; i < N; i++)``        ``cout << (arr[i]) << ``" "``;``}` `// Driver code``int` `main()``{` `    ``vector<``int``> arr;``    ``arr.push_back(3);``    ``arr.push_back(4);``    ``int` `K = 2;``    ``multiplyAllByK(arr, K);``    ``return` `0;``}` `// This code is contributed by lokeshpotta20.`

## Java

 `// Java code to implement above approach``import` `java.io.*;``import` `java.util.*;` `class` `GFG {` `    ``// Function to multiply all``    ``// the elements of array by K``    ``public` `static` `void` `multiplyAllByK(``        ``ArrayList arr, ``int` `K)``    ``{``        ``int` `N = arr.size();` `        ``// Loop to multiply all``        ``// the array elements``        ``for` `(``int` `i = ``0``; i < N; i++) {``            ``int` `x = arr.get(i);``            ``arr.set(i, K * x);``        ``}` `        ``// Print the modified array``        ``for` `(``int` `i = ``0``; i < N; i++)``            ``System.out.print(arr.get(i) + ``" "``);``    ``}` `    ``// Driver code``    ``public` `static` `void` `main(String[] args)``    ``{``        ``ArrayList arr = ``new` `ArrayList();``        ``arr.add(``3``);``        ``arr.add(``4``);``        ``int` `K = ``2``;``        ``multiplyAllByK(arr, K);``    ``}``}`

## Python

 `# Python code to implement above approach` `# Function to multiply all``# the elements of array by K``def` `multiplyAllByK(arr, K):``    ` `    ``n ``=` `len``(arr)``    ` `    ``for` `i ``in` `range``(n):``        ``x ``=` `arr[i]``        ``arr[i] ``=` `K ``*` `x``        ` `    ``for` `i ``in` `range``(n):``        ``print``(arr[i], end ``=` `' '``)` `# Driver code``arr ``=` `[``3``, ``4``]``K ``=` `2``multiplyAllByK(arr, K)` `# This code is contributed by Samim Hossain Mondal.`

## C#

 `// C# code to implement above approach` `using` `System;``using` `System.Collections.Generic;` `public` `class` `GFG {` `    ``// Function to multiply all``    ``// the elements of array by K``    ``public` `static` `void` `multiplyAllByK(``        ``List<``int``> arr, ``int` `K)``    ``{``        ``int` `N = arr.Count;` `        ``// Loop to multiply all``        ``// the array elements``        ``for` `(``int` `i = 0; i < N; i++) {``            ``int` `x = arr[i];``            ``arr[i] =( K * x);``        ``}` `        ``// Print the modified array``        ``for` `(``int` `i = 0; i < N; i++)``            ``Console.Write(arr[i] + ``" "``);``    ``}` `    ``// Driver code``    ``public` `static` `void` `Main(String[] args)``    ``{``        ``List<``int``> arr = ``new` `List<``int``>();``        ``arr.Add(3);``        ``arr.Add(4);``        ``int` `K = 2;``        ``multiplyAllByK(arr, K);``    ``}``}` `// This code is contributed by 29AjayKumar`

## Javascript

 ``

Output

`6 8 `

Time Complexity: O(N)
Auxiliary Space: O(1)

Approach Using Lambda Expression: This can also be implemented using lambda expression

n -> n * K
where n can be a particular element, or complete array.

Below is the implementation of the above approach:

## C++

 `// C++ code to implement above approach``#include ``using` `namespace` `std;` `// Function to multiply all``// the elements of array by K``void` `multiplyAllByK(``int` `arr[], ``int` `K)``{``  ``for``(``int` `i = 0; i < 2; i++)``    ``arr[i] *= K;``  ``for` `(``int` `i = 0; i < 2; i++)``    ``cout << arr[i] << ``" "``;``}` `// Driver code``int` `main()``{``  ``int` `arr[2];``  ``arr[0] = 3;``  ``arr[1] = 4;``  ``int` `K = 2;``  ``multiplyAllByK(arr, K);` `  ``return` `0;``}` `// This code is contributed by Shubham Singh`

## C

 `// C code to implement above approach``#include ` `// Function to multiply all``// the elements of array by K``void` `multiplyAllByK(``int` `arr[], ``int` `K)``{``    ``for``(``int` `i = 0; i < 2; i++) arr[i] *= K;``    ``for` `(``int` `i = 0; i<2; i++)``        ``printf``(``"%d "``,arr[i]);``}` `// Driver code``int` `main()``{``    ``int` `arr[2];``    ``arr[0] = 3;``    ``arr[1] = 4;``    ``int` `K = 2;``    ``multiplyAllByK(arr, K);``    ` `    ``return` `0;``}` `//This code is contributed by Shubham Singh`

## Java

 `// Java code to implement above approach``import` `java.io.*;``import` `java.util.*;` `class` `GFG {` `    ``// Function to multiply all``    ``// the elements of array by K``    ``public` `static` `void` `multiplyAllByK(``        ``ArrayList arr, ``int` `K)``    ``{``        ``arr.replaceAll(n -> n * K);``        ``for` `(Integer x : arr)``            ``System.out.print(x + ``" "``);``    ``}` `    ``// Driver code``    ``public` `static` `void` `main(String[] args)``    ``{``        ``ArrayList arr``            ``= ``new` `ArrayList();``        ``arr.add(``3``);``        ``arr.add(``4``);``        ``int` `K = ``2``;``        ``multiplyAllByK(arr, K);``    ``}``}`

## Python3

 `# Python3 code to implement above approach` `# Function to multiply all``# the elements of array by K``def` `multiplyAllByK(arr, K):``        ` `    ``lambda_func ``=` `lambda` `n: n ``*` `K``    ``for` `i ``in` `range``(``len``(arr)):``        ``print``(lambda_func(arr[i]), end ``=` `' '``)` `# Driver code``arr ``=` `[``3``, ``4``]``K ``=` `2` `multiplyAllByK(arr, K)` `# This code is contributed by Samim Hossain Mondal.`

## C#

 `// C# code to implement above approach``using` `System;``using` `System.Collections.Generic;``using` `System.Linq;` `public` `class` `GFG {` `    ``// Function to multiply all``    ``// the elements of array by K``    ``public` `static` `void` `multiplyAllByK(``        ``List<``int``> arr, ``int` `K)``    ``{``        ``var` `temp = arr.Select(n => n * K);``        ``foreach` `(``int` `x ``in` `temp)``            ``Console.Write(x + ``" "``);``    ``}` `    ``// Driver code``    ``public` `static` `void` `Main(String[] args)``    ``{``        ``List<``int``> arr``            ``= ``new` `List<``int``>();``        ``arr.Add(3);``        ``arr.Add(4);``        ``int` `K = 2;``        ``multiplyAllByK(arr, K);``    ``}``}` `// This code is contributed by shikhasingrajput`

## Javascript

 ``

Output

`6 8 `

Time Complexity: O(N)
Auxiliary Space: O(1)

My Personal Notes arrow_drop_up