What does History.length class method do?

Question

I typically use window.history to access the History web API, however I noticed that on MDN there is are static singleton methods/properties on the global History object such as History.length.

I noticed that History.length returns 0 that is incorrect while window.history.length returns a non-zero value that is correct.

What is the purpose of the former? Why does it return the wrong value?

Answer 1

The length property on the History constructor function is the same as for any function.

See Function.length on MDN:

The length property indicates the number of arguments expected by the function.

function foo() {};
function bar(a, b, c) {};
console.log({ foo: foo.length, bar: bar.length });

console.log("History is a " + typeof History);
console.log("history is a " + typeof history);
console.log("History is the same as history? " + (History == history));