We are a Number n and our task is multiply the number with 4 using bit-wise Operator.

Examples:

Input : 4 Output :16 Input :5 Output :20

**Explanation** Case 1:- n=4 the binary of 4 is 100 and now shift two bit right then 10000 now the number is 16 that is multiply 4*4=16 ans. **Approach** :- (n<<2) shift two bit right

## C++

`// C++ program to multiply a number with` `// 4 using Bitwise Operator` `#include <bits/stdc++.h>` `using` `namespace` `std;` `// function the return multiply a number` `// with 4 using bitwise operator` `int` `multiplyWith4(` `int` `n)` `{` ` ` `// returning a number with multiply` ` ` `// with 4 using2 bit shifring right` ` ` `return` `(n << 2);` `}` `// derive function` `int` `main()` `{` ` ` `int` `n = 4;` ` ` `cout << multiplyWith4(n) << endl;` ` ` `return` `0;` `}` |

## Java

`// Java program to multiply a number` `// with 4 using Bitwise Operator` `class` `GFG {` ` ` `// function the return` `// multiply a number` `// with 4 using bitwise` `// operator` `static` `int` `multiplyWith4(` `int` `n)` `{` ` ` ` ` `// returning a number` ` ` `// with multiply with` ` ` `// 4 using 2 bit shifting` ` ` `// right` ` ` `return` `(n << ` `2` `);` `}` `// Driver Code` `public` `static` `void` `main(String[] args)` `{` ` ` `int` `n = ` `4` `;` ` ` `System.out.print(multiplyWith4(n));` `}` `}` `// This code is contributed by Smitha.` |

## Python 3

`# Python 3 program to multiply` `# a number with 4 using Bitwise` `# Operator` `# function the return multiply` `# a number with 4 using bitwise` `# operator` `def` `multiplyWith4(n):` ` ` `# returning a number with` ` ` `# multiply with 4 using2` ` ` `# bit shifring right` ` ` `return` `(n << ` `2` `)` `# derive function` `n ` `=` `4` `print` `(multiplyWith4(n))` `# This code is contributed` `# by Smitha` |

## C#

`// C# program to multiply a number` `// with 4 using Bitwise Operator` `using` `System;` `class` `GFG {` ` ` `// function the return` `// multiply a number` `// with 4 using bitwise` `// operator` `static` `int` `multiplyWith4(` `int` `n)` `{` ` ` ` ` `// returning a number` ` ` `// with multiply with` ` ` `// 4 using 2 bit shifting` ` ` `// right` ` ` `return` `(n << 2);` `}` `// Driver Code` `public` `static` `void` `Main(String[] args)` `{` ` ` `int` `n = 4;` ` ` `Console.Write(multiplyWith4(n));` `}` `}` `// This code is contributed by Smitha.` |

## PHP

`<?php` `// PHP program to multiply` `// a number with 4 using` `// Bitwise Operator` `// function the return` `// multiply a number` `// with 4 using bitwise` `// operator` `function` `multiplyWith4(` `$n` `)` `{` ` ` ` ` `// returning a number` ` ` `// with multiply with` ` ` `// 4 using2 bit` ` ` `// shifting right` ` ` `return` `(` `$n` `<< 2);` `}` ` ` `// Driver Code` ` ` `$n` `= 4;` ` ` `echo` `multiplyWith4(` `$n` `),` `"\n"` `;` `// This code is contributed by Ajit.` `?>` |

## Javascript

`<script>` `// javascript program to multiply a number` `// with 4 using Bitwise Operator ` `// function the return` `// multiply a number` `// with 4 using bitwise` `// operator` `function` `multiplyWith4(n)` `{` ` ` ` ` `// returning a number` ` ` `// with multiply with` ` ` `// 4 using 2 bit shifting` ` ` `// right` ` ` `return` `(n << 2);` `}` `// Driver Code` `var` `n = 4;` `document.write(multiplyWith4(n));` `// This code is contributed by Amit Katiyar` `</script>` |

Output :-

16

**Generalization : **In general, we can multiply with a power of 2 using bitwise operators. For example, suppose we wish to multiply with 16 (which is 2^{4}), we can do it by left shifting by 4.

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