function foo(o) { o.f = 1; } function fu(o) { o.e = 2; } function bar(f, o) { f(o); } function baz(f, o) { f(o); } for (var i = 0; i < 100; ++i) { foo({f:1, e:2}); foo({e:1, f:2}); foo({d:1, e:2, f:3}); fu({f:1, e:2}); fu({e:1, f:2, g:3}); fu({d:1, e:2, f:3, g:4}); } for (var i = 0; i < 100; ++i) { bar(foo, {f:1}); bar(function() { }, null); bar(function() { return 42; }, null); baz(fu, {e:1}); baz(function() { }, null); baz(function() { return 42; }, null); } (function(f, g, o, p) { var result = 0; var n = 1000000; for (var i = 0; i < n; ++i) { var q; if (i == n - 1) q = p; else q = o; baz(g, q); bar(f, q); } if (o.e != 2) throw "Error: bad value in o.e: " + o.e; if (o.f != 1) throw "Error: bad value in o.f: " + o.f; if (p.e != 2) throw "Error: bad value in p.e: " + p.e; if (p.f != 1) throw "Error: bad value in p.f: " + p.f; })(foo, fu, {f:42, e:2}, {e:12, f:13, g:14});