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Find out what Typed Arrays are and how to use them
Int8Arrayan array of 8-bit signed integers
Int16Arrayan array of 16-bit signed integers
Int32Arrayan array of 32-bit signed integers
Uint8Arrayan array of 8-bit unsigned integers
Uint16Arrayan array of 16-bit unsigned integers
Uint32Arrayan array of 32-bit unsigned integers
Float32Arrayan array of 32-bit floating point numbers
Float64Arrayan array of 64-bit floating point numbers
all of them are
A Typed Array is essentially a view into an
ArrayBuffer, where every item has the same size, and type.
DataViewis another view into an ArrayBuffer, but in this case the items in the array can have different sizes and types.
Here’s an example of how to create an array of 8-bit signed integers:
const a = new Int8Array()
You can pre-allocate n bytes:
const bytes = 1024
const a = new Int8Array(bytes)
The main use is to allow to look into an ArrayBuffer, which on its own is opaque (we can’t inspect its content).
Here’s how we do so:
//we got this `buffer` ArrayBuffer
const a = new Int8Array(buffer)
Those typed arrays are array-like, so now we can inspect the content of the buffer via the usual array access techniques, and we have access to lots of methods and properties including
reduce() and so on.
One thing to keep in mind is that typed arrays don’t let us control the endianness: it uses the byte order of the platform. In general this works out fine, because the main use case as we said is to use the array locally, using one of the multimedia APIs. Also, most consumer computers use little endian since Intel uses that convention. But, if you transfer the data of a Typed Array on a system that uses big endian, the data might be badly encoded and, as such, invalid.
In case you need this kind of control over endianness, use DataView instead.