TypeError: invalid arguments

The JavaScript exception "invalid arguments" occurs when typed array constructors are provided with a wrong argument.


TypeError: invalid arguments (Firefox)

Error type


What went wrong?

Typed array constructors require either

  • a length,
  • another typed array,
  • array-like objects,
  • iterable objects or
  • an ArrayBuffer object

to create a new typed array. Other constructor arguments will not create a valid typed array.


No strings in typed arrays

Typed arrays, for example a Uint8Array, can't be constructed from a string. In fact, strings can't be in typed arrays at all.

var ta = new Uint8Array("nope");
// TypeError: invalid arguments

Different ways to create a valid Uint8Array:

// From a length
var uint8 = new Uint8Array(2);
uint8[0] = 42;
console.log(uint8[0]); // 42
console.log(uint8.length); // 2
console.log(uint8.BYTES_PER_ELEMENT); // 1

// From an array
var arr = new Uint8Array([21,31]);
console.log(arr[1]); // 31

// From another TypedArray
var x = new Uint8Array([21, 31]);
var y = new Uint8Array(x);
console.log(y[0]); // 21

// From an ArrayBuffer
var buffer = new ArrayBuffer(8);
var z = new Uint8Array(buffer, 1, 4);

// From an iterable
var iterable = function*(){ yield* [1,2,3]; }();
var uint8 = new Uint8Array(iterable);
// Uint8Array[1, 2, 3]

See also