# isASCII
> Test whether a character belongs to the [ASCII][ascii] character set and whether this is true for all characters in a provided string.
## Usage
```javascript
var isASCII = require( '@stdlib/assert/is-ascii' );
```
#### isASCII( value )
Tests whether a character belongs to the [ASCII][ascii] character set and whether this is true for all characters in a provided string.
```javascript
var bool = isASCII( 'beep' );
// returns true
```
## Notes
- For non-string values, the function returns `false`.
## Examples
```javascript
var isASCII = require( '@stdlib/assert/is-ascii' );
var out = isASCII( 'beep' );
// returns true
out = isASCII( '' );
// returns false
out = isASCII( 'È' );
// returns false
out = isASCII( 123 );
// returns false
```
* * *
## CLI
### Usage
```text
Usage: is-ascii [options] []
Options:
-h, --help Print this message.
-V, --version Print the package version.
```
### Examples
```bash
$ is-ascii beep
true
```
To use as a [standard stream][standard-streams],
```bash
$ echo -n 'beep' | is-ascii
true
```
[ascii]: https://en.wikipedia.org/wiki/ASCII
[standard-streams]: https://en.wikipedia.org/wiki/Standard_streams