michael@0: 
michael@0: var cases = [
michael@0:     function (obj) {
michael@0:         return obj["ab"];
michael@0:     },
michael@0:     function (obj) {
michael@0:         return obj["a" + "b"];
michael@0:     },
michael@0:     function (obj) {
michael@0:         return obj[0 ? "cd" : "ab"];
michael@0:     },
michael@0:     function (obj) {
michael@0:         return obj[true ? "ab" : "cd"];
michael@0:     },
michael@0:     function (obj) {
michael@0:         return obj[(1 + 0) ? "ab" : "cd"];
michael@0:     }
michael@0: ]
michael@0: 
michael@0: for (var i = 0; i < cases.length; i++) {
michael@0:     assertEq(cases[i]({ab: 42}), 42);
michael@0:     assertEq(cases[i]({cd: 120}), undefined);
michael@0: }