michael@0: function testArrayPushPop() {
michael@0:     var a = [], sum1 = 0, sum2 = 0;
michael@0:     for (var i = 0; i < 10; ++i)
michael@0:         sum1 += a.push(i);
michael@0:     for (var i = 0; i < 10; ++i)
michael@0:         sum2 += a.pop();
michael@0:     a.push(sum1);
michael@0:     a.push(sum2);
michael@0:     return a.join(",");
michael@0: }
michael@0: assertEq(testArrayPushPop(), "55,45");