JavaScript: The Definitive Guide, 6th Edition

Name

DataView — read and write values from an ArrayBuffer

Inherits from

ArrayBufferView

Synopsis

A DataView is an ArrayBufferView that wraps an ArrayBuffer (or a region of an array buffer) and defines methods for reading and writing 1-, 2-, and 4-byte signed and unsigned integers and 4- and 8-byte floating-point numbers from or into the buffer. The methods support both big-endian and little-endian byte orders. See also TypedArray.

Constructor

new DataView(ArrayBuffer buffer, 
             [unsigned long byteOffset], [unsigned long byteLength])

This constructor creates a new DataView object that allows read and write access to the bytes in buffer or a region of buffer. With one argument, it creates a view of the entire buffer. With two arguments, it creates a view that extends from byte number byteOffset to the end of the buffer. And with three arguments, it creates a view of the byteLength bytes starting at byteOffset.

Methods

Each of these method reads a numeric value from, or writes a numeric value into, the underlying ArrayBuffer. The method name specifies the type that is read or written. All methods that read or write more than one byte accept an optional final littleEndian argument. If this argument is omitted, or is false, big-endian byte ordering is used, with the most significant bytes being read or written first. If the argument is true, however, little-endian byte ordering is used.

float getFloat32(unsigned long byteOffset, [boolean littleEndian])

Interpret the 4 bytes starting at byteOffset ...