function testValue() { function f(arr, x) { return arr[x]; } var a = [1, undefined, null, Math, 2.1, ""]; for (var i=0; i<50; i++) { assertEq(f(a, 0), 1); assertEq(f(a, 1), undefined); assertEq(f(a, 2), null); assertEq(f(a, 3), Math); assertEq(f(a, 4), 2.1); assertEq(f(a, 5), ""); assertEq(f(a, -1), undefined); assertEq(f(a, 6), undefined); } } testValue(); function testOutOfBounds() { function f(arr, x) { return arr[x]; } var a = [0, 1, 2, 3, 4]; for (var j=0; j<4; j++) { for (var i=0; i<5; i++) { assertEq(f(a, i), i); } for (var i=5; i<10; i++) { assertEq(f(a, i), undefined); } for (var i=-1; i>-10; i--) { assertEq(f(a, i), undefined); } } } testOutOfBounds(); function testHole() { function f(arr, x) { return arr[x]; } var a = [0, , 2, ]; for (var i=0; i<70; i++) { assertEq(f(a, 0), 0); assertEq(f(a, 1), undefined); assertEq(f(a, 2), 2); assertEq(f(a, 3), undefined); } } testHole(); function testClassGuard() { function f(arr) { return arr[2]; } var a = [1, 2, 3, 4]; for (var i=0; i<90; i++) { assertEq(f(a), 3); } var b = {2: 100}; assertEq(f(b), 100); } testClassGuard(); function testGeneric1() { function f(o, i) { return o[i]; } for (var i=0; i<100; i++) { assertEq(f("abc", 1), "b"); assertEq(f("foo", "length"), 3); assertEq(f([], -1), undefined); assertEq(f({x: 1}, "x"), 1); } } testGeneric1();