# Set the K-th bit of a given number

• Difficulty Level : Easy
• Last Updated : 19 Jul, 2022

Given a number n and a value k. From the right, set the kth bit in the binary representation of n. The position of LSB(or last bit) is 0, second last bit is 1 and so on. Also, 0 <= k < x, where x is the number of bits in the binary representation of n.
Examples:

```Input : n = 10, k = 2
Output : 14
(10)10 = (1010)2
Now, set the 2nd bit from right.
(14)10 = (1110)2
2nd bit has been set.

Input : n = 15, k = 3
Output : 15
3rd bit of 15 is already set.```

To set any bit we use bitwise OR | operator. As we already know bitwise OR | operator evaluates each bit of the result to 1 if any of the operand’s corresponding bit is set (1). In-order to set kth bit of a number we need to shift 1 k times to its left and then perform bitwise OR operation with the number and result of left shift performed just before.

`                            In general, (1 << k) | n.`

## C++

 `// C++ implementation to set the kth bit``// of the given number``#include ` `using` `namespace` `std;` `// function to set the kth bit``int` `setKthBit(``int` `n, ``int` `k)``{``    ``// kth bit of n is being set by this operation``    ``return` `((1 << k) | n);``}` `// Driver program to test above``int` `main()``{``    ``int` `n = 10, k = 2;``    ``cout << ``"Kth bit set number = "``         ``<< setKthBit(n, k);``    ``return` `0;``}`

## Java

 `// Java implementation to set the kth bit``// of the given number` `class` `GFG {``    ` `// function to set the kth bit``static` `int` `setKthBit(``int` `n, ``int` `k)``{``    ``// kth bit of n is being set by this operation``    ``return` `((``1` `<< k) | n);``}` `// Driver code``public` `static` `void` `main(String arg[])``{``    ``int` `n = ``10``, k = ``2``;``    ``System.out.print(``"Kth bit set number = "` `+``                             ``setKthBit(n, k));``}``}` `// This code is contributed by Anant Agarwal.`

## Python3

 `# Python implementation``# to set the kth bit``# of the given number` `# function to set``# the kth bit``def` `setKthBit(n,k):` `    ``# kth bit of n is being``    ``# set by this operation``    ``return` `((``1` `<< k) | n)``    ` `# Driver code` `n ``=` `10``k ``=` `2` `print``(``"Kth bit set number = "``,``          ``setKthBit(n, k))` `# This code is contributed``# by Anant Agarwal.`

## C#

 `// C# implementation to set the``// kth bit of the given number``using` `System;` `class` `GFG {``    ` `// function to set the kth bit``static` `int` `setKthBit(``int` `n, ``int` `k)``{``    ``// kth bit of n is being set``    ``// by this operation``    ``return` `((1 << k) | n);``}` `// Driver code``public` `static` `void` `Main()``{``    ``int` `n = 10, k = 2;``    ``Console.Write(``"Kth bit set number = "``                    ``+ setKthBit(n, k));``                   ` `}``}` `// This code is contributed by``// Smitha Dinesh Semwal.`

## PHP

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## Javascript

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Output:

`Kth bit set number = 14`

Time Complexity: O(1)

Auxiliary Space: O(1)
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