# ArrayBuffer
> [Constructor][mdn-arraybuffer] which returns an object used to represent a generic, fixed-length raw binary data buffer.
## Usage
```javascript
var ArrayBuffer = require( '@stdlib/array/buffer' );
```
#### ArrayBuffer( size )
Returns an [`ArrayBuffer`][mdn-arraybuffer] having a specified number of bytes.
```javascript
var buf = new ArrayBuffer( 5 );
// returns
```
* * *
### Properties
#### ArrayBuffer.length
Number of input arguments the constructor accepts.
```javascript
var len = ArrayBuffer.length;
// returns 1
```
#### ArrayBuffer.prototype.byteLength
**Read-only** property which returns the length (in bytes) of the [`ArrayBuffer`][mdn-arraybuffer].
```javascript
var buf = new ArrayBuffer( 5 );
var byteLength = buf.byteLength;
// returns 5
```
* * *
### Methods
#### ArrayBuffer.isView( arr )
Static method which returns a `boolean` indicating if provided a buffer view.
```javascript
var Float64Array = require( '@stdlib/array/float64' );
var view = new Float64Array( 10 );
var bool = ArrayBuffer.isView( view );
// returns true
```
#### ArrayBuffer.prototype.slice( \[start\[, end]] )
Copies the bytes of an `ArrayBuffer` to a new [`ArrayBuffer`][mdn-arraybuffer].
```javascript
var b1 = new ArrayBuffer( 10 );
var b2 = b1.slice();
// returns
var bool = ( b2 === b1 );
// returns false
```
By default, the method copies from the beginning of the [`ArrayBuffer`][mdn-arraybuffer]. To beginning copying from a different byte index, provide a `start` argument, specifying the starting byte index (inclusive).
```javascript
var b1 = new ArrayBuffer( 10 );
var b2 = b1.slice( 2 );
var nbytes = b2.byteLength;
// returns 8
```
If `start < 0`, the index is relative to the end of the [`ArrayBuffer`][mdn-arraybuffer].
```javascript
var b1 = new ArrayBuffer( 10 );
var b2 = b1.slice( -2 );
var nbytes = b2.byteLength;
// returns 2
```
By default, the method copies to the end of the [`ArrayBuffer`][mdn-arraybuffer]. To copy until a particular byte index, provide an `end` index, specifying the ending byte index (exclusive).
```javascript
var b1 = new ArrayBuffer( 10 );
var b2 = b1.slice( 2, 6 );
var nbytes = b2.byteLength;
// returns 4
```
If `end < 0`, the index is relative to the end of the [`ArrayBuffer`][mdn-arraybuffer].
```javascript
var b1 = new ArrayBuffer( 10 );
var b2 = b1.slice( 2, -2 );
var nbytes = b2.byteLength;
// returns 6
```
* * *
## Examples
```javascript
var randu = require( '@stdlib/random/base/randu' );
var Float64Array = require( '@stdlib/array/float64' );
var Uint8Array = require( '@stdlib/array/uint8' );
var toBinaryString = require( '@stdlib/number/uint8/base/to-binary-string' );
var ArrayBuffer = require( '@stdlib/array/buffer' );
var bytes;
var buf;
var arr;
var i;
// Create a new ArrayBuffer:
buf = new ArrayBuffer( 64 );
// Create a Float64 array buffer view:
arr = new Float64Array( buf.byteLength/8 );
for ( i = 0; i < arr.length; i++ ) {
arr[ i ] = randu() * 100.0;
}
// Create a "bytes" view of the array buffer:
bytes = new Uint8Array( arr.buffer );
// Print the bytes:
for ( i = 0; i < bytes.length; i++ ) {
console.log( 'byte %d: %s', i, toBinaryString( bytes[ i ] ) );
}
```
[mdn-arraybuffer]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer