ArrayBuffer,

- (, ). .

JavaScript, , .

. :

• ArrayBuffer, Uint8Array, DataView, Blob, File .

JavaScript , . , , .

ArrayBuffer .

:

let buffer = new ArrayBuffer(16); //     16
alert(buffer.byteLength); // 16

16 .

ArrayBuffer . ? , .

ArrayBuffer .

. , ArrayBuffer.

:

• Uint8Array ArrayBuffer 0 255 ( 8 , ). 8- .
• Uint16Array 2 0 65535. 16- .
• Uint32Array 4 0 4294967295. 32- .
• Float64Array 8 5.0x10-324 1.8x10308.

, 16 ArrayBuffer 16 8 (2 ), 4 (4 ), 2 (8 ).

[]

ArrayBuffer , .

, - :

let buffer = new ArrayBuffer(16); //     16

let view = new Uint32Array(buffer); //    32-  

alert(Uint32Array.BYTES_PER_ELEMENT); // 4    

alert(view.length); // 4,    
alert(view.byteLength); // 16,   

//   
view[0] = 123456;

//   
for(let num of view) {
  alert(num); // 123456,  0, 0, 0 ( 4 )
}

TypedArray

(Uint8Array, Uint32Array ) TypedArray. .

, TypedArray, , ArrayBuffer: Int8Array, Uint8Array .

new TypedArray - new Int8Array, new Uint8Array .

: .

(Int8Array Float64Array, ) - .

5 :

new TypedArray(buffer, [byteOffset], [length]);
new TypedArray(object);
new TypedArray(typedArray);
new TypedArray(length);
new TypedArray();

1. ArrayBuffer, . .

   : byteOffset ( 0) length ( ) buffer.

2. Array - .

   :

   let arr = new Uint8Array([0, 1, 2, 3]);
   alert( arr.length ); // 4,      
   alert( arr[1] ); // 1,   4  (8-   )   

3. TypedArray : . , .

   let arr16 = new Uint16Array([1, 1000]);
   let arr8 = new Uint8Array(arr16);
   alert( arr8[0] ); // 1
   alert( arr8[1] ); // 232,   1000,  8      1000 ( )

4. length . length TypedArray.BYTES_PER_ELEMENT:

   let arr = new Uint16Array(4); //     4  
   alert( Uint16Array.BYTES_PER_ELEMENT ); // 2   
   alert( arr.byteLength ); // 8 (  )

5. .

TypedArray , ArrayBuffer. ArrayBuffer, ( ArrayBuffer ).

ArrayBuffer TypedArray :

• buffer ArrayBuffer.
• byteLength ArrayBuffer.

, :

let arr8 = new Uint8Array([0, 1, 2, 3]);

//    
let arr16 = new Uint16Array(arr8.buffer);

:

• Uint8Array, Uint16Array, Uint32Array 8, 16 32 .
  • Uint8ClampedArray 8- , ( ).
• Int8Array, Int16Array, Int32Array ( ).
• Float32Array, Float64Array 32 64 .

, ? , .

, 256 Uint8Array. 256 100000000 (9 ), Uint8Array 8 , 0 255.

( ) 8 , .

[]

.

257 100000001 (9 ), 8 , 1:

[]

, 28.

:

let uint8array = new Uint8Array(16);

let num = 256;
alert(num.toString(2)); // 100000000 ( )

uint8array[0] = 256;
uint8array[1] = 257;

alert(uint8array[0]); // 0
alert(uint8array[1]); // 1

Uint8ClampedArray , . 255 , 255 0 . .

TypedArray

TypedArray Array, .

map, slice, find, reduce .

, :

• splice . , , -- . .
• concat.

2 :

• arr.set(fromArr, [offset]) , offset ( 0) fromArr arr.
• arr.subarray([begin, end]) begin end ( ). slice ( ), .

, , .

DataView

DataView ArrayBuffer. - - .

• . . i- arr[i].
• DataView .getUint8(i) .getUint16(i). , .

:

new DataView(buffer, [byteOffset], [byteLength])

• buffer ArrayBuffer. DataView . .
• byteOffset ( 0).
• byteLength ( buffer).

, :

//    4 ,      255
let buffer = new Uint8Array([255, 255, 255, 255]).buffer;

let dataView = new DataView(buffer);

//  8-    0
alert( dataView.getUint8(0) ); // 255

//   16-    0,    2 ,     65535
alert( dataView.getUint16(0) ); // 65535 ( 16-   )

//  32-    0
alert( dataView.getUint32(0) ); // 4294967295 ( 32-   )

dataView.setUint32(0, 0); //  4-   ,      0

DataView , . , (16- , 32- ), DataView .

ArrayBuffer , .

ArrayBuffer .

• TypedArray:
  • Uint8Array, Uint16Array, Uint32Array 8, 16 32 .
  • Uint8ClampedArray 8- , .
  • Int8Array, Int16Array, Int32Array ( ).
  • Float32Array, Float64Array 32 64 .
• DataView , getUint8(offset).

, ArrayBuffer . , .buffer .

, :

• ArrayBufferView .
• BufferSource , ArrayBuffer ArrayBufferView.

. BufferSource - ArrayBuffer .

:

[]