// A for-of loop over an array stops at the new end of the array if it shrinks during iteration.
function ispal(arr) {
for (var v of arr) {
if (v !== arr.pop())
return false;
}
return true;
}
assertEq(ispal([1, 2, 3, 4, 3, 2, 1]), true);
assertEq(ispal([1, 2, 3, 3, 2, 1]), true);
assertEq(ispal([1, 2, 3, 4, 2, 1]), false);