Function whos parameter is not called

What happens when you have a function who’s parameter is not called. Ex.

// When you open a new tab at the end
Window.prototype.tabOpen = function (tab) {
  this.tabs.push('new tab'); // Let's open a new tab for now
  return this;

2 posts were merged into an existing topic: Coding question andrej

Please do not create duplicate topics for the same challenge/project question(s). This duplicate topic has been unlisted.

Thank you.