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 multipy ` ` ` `// with 4 using2 bit shifring right ` ` ` `return` `(n << 2); ` `} ` ` ` `// derive function ` `int` `main() ` `{ ` ` ` `int` `n = 4; ` ` ` `cout << multiplyWith4(n) << endl; ` ` ` `return` `0; ` `} ` |

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## 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 multipy 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. ` |

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## 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 ` ` ` `# multipy with 4 using2 ` ` ` `# bit shifring right ` ` ` `return` `(n << ` `2` `) ` ` ` `# derive function ` `n ` `=` `4` `print` `(multiplyWith4(n)) ` ` ` `# This code is contributed ` `# by Smitha ` |

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## 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 multipy 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. ` |

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## 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(` `$n` `) ` `{ ` ` ` ` ` `// returning a number ` ` ` `// with multipy with ` ` ` `// 4 using2 bit ` ` ` `// shifting right ` ` ` `return` `(` `$n` `<< 2); ` `} ` ` ` ` ` `// Driver Code ` ` ` `$n` `= 4; ` ` ` `echo` `multiplyWith4(` `$n` `),` `"\n"` `; ` ` ` `// This code is contributed by Ajit. ` `?> ` |

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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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