Why is the value of Float32Array.length always 3?

Question

I was reading the Mozilla Developer Network docs on Float32Arrays when I came upon

Float32Array.length
Length property whose value is 3.

... why is always 3? I also noticed that prototype property of the same name overrides it.

Answer 1

Float32Array is actually a function. You can check that like this

console.assert(typeof Float32Array === 'function');

And that function accepts three parameters. Quoting the signature from the same documentation,

Float32Array(buffer [, byteOffset [, length]]);

Quoting the Function.length documentation,

length is a property of a function object, and indicates how many arguments the function expects, i.e. the number of formal parameters.

That is why the length property of Float32Array is always 3.