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

It's because the constructor takes up to 3 arguments:

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

Every function in JavaScript has a length property that will return the count of the named parameters it takes.

E.g.

function foo(a, b) {}
foo.length === 2; // true

function bar() {}
bar.length === 0; // true