---
title: 3.17 Bitwise NOT Operator (~)
description: "The bitwise NOT operator (`~`) is a unary operator that inverts every bit of its operand. Each bit with the value `1` becomes `0`, and each bit with the value `0` becomes `1`. The bitwise NOT operator is commonly used…"
url: "https://edcret.in/docs/cpp-programming/operators-cplusplus/3-17-bitwise-not-operator/"
updated: "2026-07-28"
category: C++ Programming / Operators
---

# 3.17 Bitwise NOT Operator (~)

The bitwise NOT operator (`~`) is a unary operator that inverts every bit of its operand. Each bit with the value `1` becomes `0`, and each bit with the value `0` becomes `1`.

The bitwise NOT operator is commonly used in bit manipulation tasks such as creating bit masks and clearing selected bits. It operates only on integral data types.

## Source Code

```
#include <iostream>

int main()
{
    int number = 12;

    int result = ~number;

    std::cout << "Number : " << number << '\n';
    std::cout << "Result : " << result << '\n';

    return 0;
}
```

## Output

```
Number : 12
Result : -13
```

## Explanation

- The bitwise NOT operator (`~`) is a unary operator that operates on a single integral operand.
- It inverts every bit of the operand by changing `1` bits to `0` and `0` bits to `1`.
- The binary representation of `12` is:`12 = 00000000 00000000 00000000 00001100`
- After applying the bitwise NOT operator:`~12 = 11111111 11111111 11111111 11110011`
- On most modern systems that use two's complement representation, the resulting bit pattern represents the decimal value `-13`.
- The exact binary representation depends on the size of the integer type, but the numerical result is typically `-13` for a 32-bit `int`.
- Bitwise NOT is commonly used when constructing masks to clear or invert selected bits.
- `return 0;` terminates the program successfully.