Float64Array() constructor

The Float64Array() typed array constructor creates a new Float64Array object, which is, an array of 64-bit floating point numbers (corresponding to the C double data type) in the platform byte order. If control over byte order is needed, use DataView instead. The contents are initialized to 0. 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).


new Float64Array()
new Float64Array(length)
new Float64Array(typedArray)
new Float64Array(object)

new Float64Array(buffer)
new Float64Array(buffer, byteOffset)
new Float64Array(buffer, byteOffset, length)

Note: Float64Array() can only be constructed with new. Attempting to call it without new throws a TypeError.




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);
// Float64Array [1, 2, 3]


ECMAScript Language Specification
# sec-typedarray-constructors

Browser compatibility

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See also