TypedArray demonstrates an array-like view of a binary data buffer. They are introduced in ECMAScript version 6 to handle binary data. There is no keyword reserved ‘TypedArray’, nor is there a directly visible TypedArray constructor.
There are several types of TypedArray shown below with there range, size, web IDL Type, Equivalent C Type:
|
Type |
Range Value |
Size (Bytes) |
Web IDL Type |
Equivalent C type |
|
Int8Array |
-128 to 127 |
1 |
byte |
int8_t |
|
Uint8Array |
0 to 255 |
1 |
octet |
uint8_t |
|
Uint8ClampedArray |
0 to 255 |
1 |
octet |
uint8_t |
|
Int16Array |
-32768 to 32767 |
2 |
short |
int16_t |
|
Uint16Array |
0 to 65535 |
2 |
unsigned short |
uint16_t |
|
Int32Array |
-2147483648 to 2147483647 |
4 |
long |
int32_t |
|
Uint32Array |
0 to 4294967295 |
4 |
unsigned long |
uint32_t |
|
Float32Array |
1.2×10^-38 to 3.4×10^38 |
4 |
unrestricted float |
float |
|
Float64Array |
5.0×10^-324 to 1.8×10^308 |
8 |
unrestricted double |
double |
|
BigInt64Array |
-2^63 to 2^63-1 |
8 |
bigint |
int64_t (signed long long) |
|
BigUint64Array |
0 to 2^64-1 |
8 |
bigint |
uint64_t (unsigned long long) |
Constructor: This object cannot be instantiated directly. Instead, you have to create an instance of an array of a particular type, such as an UInt8Array or a BigInt64Array.
When creating an instance of a TypedArray(e.g. Int8Array), an Array Buffer instance is also created internally in the memory or, if an ArrayBuffer object is given as a constructor argument, then that argument is used instead.
We can create the instance of TypedArray by using the ‘new’ keyword with the respective constructor.
Syntax:
new TypedArray(); // Or new TypedArray(length); // Or new TypedArray(typedArray); // Or new TypedArray(object); // Or new TypedArray(buffer [, byteOffset [, length]]);
TypedArray can be any type mention above.
Parameters: Below are the parameter which TypedArray can take:
- length: The size of ArrayBuffer to create.
- typedArray: Type of array to be created.
- object: When called with the object argument, a new typed array instance is created.
- buffer, byteOffset, length: When called with a buffer,byteOffset, and a length argument, a new typed array view is created that is used to view the specified ArrayBuffer.
Instantiating a TypedArray: Below are some examples that show how to instantiate a TypedArray.
Example 1:
Javascript
const buffer = new ArrayBuffer(8); // Initiating using the constructor const uint8 = new Uint8Array(buffer); // Output is 8 as we initiated the length with 8 console.log(uint8.length); |
Output:
Example 2:
Javascript
const int8 = new Int8Array([0, 0, 0, 0]); int8.fill(4, 1, 3); console.log(int8); |
Output:
Example 3: Checking if the values are contained inside the TypedArray.
Javascript
const int8 = new Int8Array([10, 20, 30, 40, 50]); console.log(int8.includes(20)); console.log(int8.includes(20, 3)); |
Output:
