The fill() method of TypedArray instances changes all elements within a range of indices in a typed array to a static value. It returns the modified typed array. This method has the same algorithm as Array.prototype.fill().

Try it

const uint8 = new Uint8Array([0, 0, 0, 0]);
// Value, start position, end position
uint8.fill(4, 1, 3);

console.log(uint8);
// Expected output: Uint8Array [0, 4, 4, 0]

Syntax

fill(value)
fill(value, start)
fill(value, start, end)

Parameters

value

Value to fill the typed array with.

start Optional

Zero-based index at which to start filling, converted to an integer.

end Optional

Zero-based index at which to end filling, converted to an integer. fill() fills up to but not including end.

Return value

The modified typed array, filled with value.

Description

See Array.prototype.fill() for more details. This method is not generic and can only be called on typed array instances.

Examples

Using fill()

new Uint8Array([1, 2, 3]).fill(4); // Uint8Array [4, 4, 4]
new Uint8Array([1, 2, 3]).fill(4, 1); // Uint8Array [1, 4, 4]
new Uint8Array([1, 2, 3]).fill(4, 1, 2); // Uint8Array [1, 4, 3]
new Uint8Array([1, 2, 3]).fill(4, 1, 1); // Uint8Array [1, 2, 3]
new Uint8Array([1, 2, 3]).fill(4, -3, -2); // Uint8Array [4, 2, 3]

Specifications

Browser compatibility

See also

• Polyfill of TypedArray.prototype.fill in core-js
• JavaScript typed arrays guide
• TypedArray
• Array.prototype.fill()