JavaScript Uint8ClampedArray : Object

constructor

Uint8ClampedArray is similar to an Array where each item is a 8 bit (1 byte) unsigned integer. Values stored in this array are clamped to the range 0-255. Uint8ClampedArrays cannot change size after creation.

Spec

Constructors

new Uint8ClampedArray(length : Number) : Uint8ClampedArray

Creates a new Uint8ClampedArray of the specified length where each item starts out as 0

Example:

var x = new Uint8ClampedArray(3);
x[0] = -17;
x[1] = 93;
x[2] = 350;
console.log(x[0]);
console.log(x[1]);
console.log(x[2]);
console.log(x.length);

Run

Results:

new Uint8ClampedArray(array : Array) : Uint8ClampedArray

Creates a new Uint8ClampedArray and copies the items of array into this. The copied items are converted to 8 bit integers before being stored in this.

Example:

var x = new Uint8ClampedArray([17, -45.3]);
console.log(x[0]);
console.log(x[1]);
console.log(x.length);

Run

Results:

new Uint8ClampedArray(array : Uint8ClampedArray) : Uint8ClampedArray

Creates a new Uint8ClampedArray and copies the items of array into this. array can be any of the typed array types and the copied items will be converted to 8 bit integers before being stored in this.

Example:

var x = new Uint8ClampedArray([17, -45.3]);
var y = new Uint8ClampedArray(x);
console.log(x[0]);
console.log(x[1]);
console.log(x.length);
x[0] = -2;
console.log(y[0]); // y is not modified

Run

Results:

new Uint8ClampedArray(buffer : ArrayBuffer, [byteOffset = 0 : Number, [length : Number]]) : Uint8ClampedArray

Creates a view on top of the specified buffer starting at byteOffset of length items. Changes to the items in this actual affect the underlying buffer, and vice versa. byteOffset must be a multiple of 4. (Use DataView for unaligned data.) If length is not specified, the returned Uint8ClampedArray's buffer.length - byteOffset must be a multiple of 4 and this.length will be (buffer.length - byteOffset) / 4.

Example:

var buffer = new ArrayBuffer(12);
var x = new Uint8ClampedArray(buffer, 0, 2);
// Make another view of last 4 bytes of the buffer
var y = new Uint8ClampedArray(buffer, 4, 1);
x[1] = 7;
console.log(y[0]); // y is a live view on the buffer

Run

Results:

Instance Properties

buffer : ArrayBuffer

Returns the underlying buffer for this Uint8ClampedArray.

Example:

var buffer = new ArrayBuffer(12);
var x = new Uint8ClampedArray(buffer, 0, 2);
var y = new Uint8ClampedArray(x.buffer, 4, 2);
console.log(x.buffer === y.buffer);

Run

Results:

byteLength : Number

The length of this in bytes.

Example:

var buffer = new ArrayBuffer(12);
var x = new Uint8ClampedArray(buffer, 4, 2);
console.log(x.byteLength); 
console.log(x.length * Uint8ClampedArray.BYTES_PER_ELEMENT);

Run

Results:

byteOffset : Number

The offset into this.buffer where the 0th item is stored.

Example:

var buffer = new ArrayBuffer(12);
var x = new Uint8ClampedArray(buffer, 4, 2);
console.log(x.byteOffset);

Run

Results:

length : Number

The number of elements in this. It is 1 greater than the index of the last item.

Example:

var x = new Uint8ClampedArray(10);
console.log(x.length);

Run

Results:

Instance Methods

set 2 variants

set(array : Array, [offset = 0 : Number]) : undefined

Copies items from array into this starting at this[offset]. Copied items are converted to 8 bit ints before storing in this.

Example:

var x = new Uint8ClampedArray(10);
x.set([18, 93, 42], 3);
console.log(x[3]);
console.log(x[4]);
console.log(x[5]);

Run

Results:

set(array : Uint8ClampedArray, [offset = 0 : Number]) : undefined

Copies items from array into this starting at this[offset]. array can be any of the typed array types and the copied items will be converted to 8 bit ints before storing in this.

Example:

var x = new Uint8ClampedArray(10);
x.set(new Uint8ClampedArray([18, 93, 42]), 3);
console.log(x[3]);
console.log(x[4]);
console.log(x[5]);

Run

Results:

subarray(begin : Number, [end : Number]) : Uint8ClampedArray

Returns a new Uint8ClampedArray that is a view on top of this containing items this[begin], this[begin + 1], ..., this[end - 1]. The 0th item in the returned array in the same memory location as this[begin]. If end is not specified, this.length is used.

Example:

var x = new Uint8ClampedArray([0, 1, 2, 3, 4, 5]); // length=6
var y = x.subarray(2, 5);
console.log(y.length);
console.log(y[0]);
console.log(y[1]);
y[0] = -1;
console.log(x[2]);

Run

Results:

Uint8ClampedArray Properties

BYTES_PER_ELEMENT : Number

Returns the size in bytes of an item in an Uint8ClampedArray.

Example:

console.log(Uint8ClampedArray.BYTES_PER_ELEMENT);

Run

Results:

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