stdlib/lib/node_modules/@stdlib/array/buffer at develop

ArrayBuffer

Constructor which returns an object used to represent a generic, fixed-length raw binary data buffer.

Usage

var ArrayBuffer = require( '@stdlib/array/buffer' );

ArrayBuffer( size )

Returns an ArrayBuffer having a specified number of bytes.

var buf = new ArrayBuffer( 5 );
// returns <ArrayBuffer>

Properties

ArrayBuffer.length

Number of input arguments the constructor accepts.

var len = ArrayBuffer.length;
// returns 1

ArrayBuffer.prototype.byteLength

Read-only property which returns the length (in bytes) of the ArrayBuffer.

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.

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.

var b1 = new ArrayBuffer( 10 );

var b2 = b1.slice();
// returns <ArrayBuffer>

var bool = ( b2 === b1 );
// returns false

By default, the method copies from the beginning of the ArrayBuffer. To beginning copying from a different byte index, provide a start argument, specifying the starting byte index (inclusive).

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.

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. To copy until a particular byte index, provide an end index, specifying the ending byte index (exclusive).

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.

var b1 = new ArrayBuffer( 10 );
var b2 = b1.slice( 2, -2 );

var nbytes = b2.byteLength;
// returns 6

Examples

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 ] ) );
}