# not, ~

Find logical NOT

## Syntax

``~A``
``not(A)``

## Description

example

````~A` returns a logical array of the same size as `A`. The array contains logical `1` (`true`) values where `A` is zero and logical `0` (`false`) values where `A` is nonzero.```
````not(A)` is an alternate way to execute `~A`, but is rarely used. It enables operator overloading for classes.```

## Examples

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Create a 3-by-3 identity matrix.

`A = eye(3)`
```A = 3×3 1 0 0 0 1 0 0 0 1 ```

Find the logical negation of `A`. The new matrix has type `logical`.

`B = ~A`
```B = 3x3 logical array 0 1 1 1 0 1 1 1 0 ```

Execute code based on a condition using the logical not operator in the context of an `if` loop.

Create a logical variable `A`.

`A = false;`

Use `A` to write an if/else code block. Wrap the if/else block in a `for` loop so that it executes four times.

```for k = 1:4 if ~A disp('IF block') A = true; else disp('ELSE block') end end```
```IF block ```
```ELSE block ELSE block ELSE block ```

On the first iteration, `A` is `false`, so the `if` block executes since `~A` is `true`. However, the `if` block also changes the value of `A` to `true`. In the remaining iterations, `~A` is `false` and the `else` block executes.

## Input Arguments

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Input array, specified as a numeric scalar, vector, matrix, or multidimensional array.

Data Types: `single` | `double` | `int8` | `int16` | `int32` | `int64` | `uint8` | `uint16` | `uint32` | `uint64` | `logical` | `char`
Complex Number Support: Yes

## Tips

• You also can use the `~` symbol as a placeholder output argument in a function call. For example, ```[~,i] = max(A)``` suppresses the first output of the `max` function, returning only the indices of the maximum values. For more information, see Ignore Inputs in Function Definitions.