Float64Array
Baseline
Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
The Float64Array typed array represents an array of 64-bit floating point numbers in the platform byte order. If control over byte order is needed, use DataView instead. The contents are initialized to 0 unless initialization data is explicitly provided. Once established, you can reference elements in the array using the object's methods, or using standard array index syntax (that is, using bracket notation).
Float64Array is a subclass of the hidden TypedArray class.
Constructor
Float64Array()-
Creates a new
Float64Arrayobject.
Static properties
Also inherits static properties from its parent TypedArray.
Float64Array.BYTES_PER_ELEMENT-
Returns a number value of the element size.
8in the case ofFloat64Array.
Static methods
Inherits static methods from its parent TypedArray.
Instance properties
Also inherits instance properties from its parent TypedArray.
These properties are defined on Float64Array.prototype and shared by all Float64Array instances.
Float64Array.prototype.BYTES_PER_ELEMENT-
Returns a number value of the element size.
8in the case of aFloat64Array. Float64Array.prototype.constructor-
The constructor function that created the instance object. For
Float64Arrayinstances, the initial value is theFloat64Arrayconstructor.
Instance methods
Inherits instance methods from its parent TypedArray.
Examples
Different ways to create a Float64Array
// From a length
const float64 = new Float64Array(2);
float64[0] = 42;
console.log(float64[0]); // 42
console.log(float64.length); // 2
console.log(float64.BYTES_PER_ELEMENT); // 8
// From an array
const x = new Float64Array([21, 31]);
console.log(x[1]); // 31
// From another TypedArray
const y = new Float64Array(x);
console.log(y[0]); // 21
// From an ArrayBuffer
const buffer = new ArrayBuffer(64);
const z = new Float64Array(buffer, 8, 4);
console.log(z.byteOffset); // 8
// From an iterable
const iterable = (function* () {
yield* [1, 2, 3];
})();
const float64FromIterable = new Float64Array(iterable);
console.log(float64FromIterable);
// Float64Array [1, 2, 3]
Specifications
| Specification |
|---|
| ECMAScript® 2026 Language Specification # sec-typedarray-objects |