Ambiguity of vars in functions objects and methods?

Question

Is there a purposes for using the same name for variables in object constructors, within the object code and within the methods contained inside the object; when calling them is handled differently for each? ie

function confusing(a, b) {
this.a = a;
this.b = b;
this.confused = function (a) {
this.a = a;
}
}

var c = new confusing("Yes", "No");
document.write("a is "+ c.a);
c.confused("No");

document.write(" and a is "+c.a);

Answer 1

Now that you have seen that this can be confusing, take it as a lesson, and evade such practices in your own codes 👍