# isvar

Check for the existence of an variable.

## Syntax

* tf = isvar(varname)
* tf = isvar(scope, varname)

## Input argument

* scope - a string: 'global', 'base', 'caller', 'local'.
* varname - a string: variable name.

## Output argument

* tf - a logical: true if varname exists.

## Description

**isvar** checks for the existence of an variable.

## Example

```matlab
isvar('A')
A = 3
isvar('A')
isvar('global','B')
global B
isvar('global','B')
```

## See also

[exist](../core/exist).

## History

| Version | Description     |
| ------- | --------------- |
| 1.0.0   | initial version |

## Author

Allan CORNET
