in.js (344B)
1 function f(arr, b) { 2 var res = ""; 3 var a; 4 if (b) 5 a = arr; 6 for (var i=100; i>-200; i--) { 7 if (i in a) { 8 res += i; 9 } 10 } 11 return res; 12 } 13 14 assertEq(f([1, , 2, 3], true), "320"); 15 16 try { 17 f([1, , 2, 3], false); 18 assertEq(0, 1); 19 } catch(e) { 20 assertEq(e instanceof TypeError, true); 21 }