# Set the K-th bit of a given number

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

 ``

Output:

`Kth bit set number = 14`

Time Complexity: O(1)

Auxiliary Space: O(1)

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