Wikipedia:WikiProject User scripts/Scripts/Get Page Name

Returns the name of the page. For example, if you were browsing the "foo" WP page, getPname() would return "foo".

function getPname() {
  z=document.getElementById("content").childNodes;
  for (var n=0;n<z.length;n++) { 
    if (z[n].className=="firstHeading") return z[n].textContent;
  };
}

This code was taken from the Show last diff code.