michael@0: // for-of does not skip Array holes. The value at a hole is undefined.
michael@0: 
michael@0: var a = [0, , 2, 3];
michael@0: var log = [];
michael@0: for (var x of a) {
michael@0:     assertEq(x, a[log.length]);
michael@0:     log.push(x);
michael@0: }
michael@0: assertEq(log[1], undefined);
michael@0: assertEq(log.join(), "0,,2,3");