for (  i=0; i<arr.length; i++ ) {
    console.log(arr[i])
}
console.log("=============================================")
var arr1 = arr.slice();
for ( var i in arr1.reverse() ) {
    console.log(arr1[i])
}
console.log("=============================================")
var k = 0;
while( arr[k] ) {
   console.log( arr[k++] )
}
console.log("=============================================")
var arr2 = arr.slice().reverse();
var j = 0;
do {
  console.log(arr2[j++]);
} while (j < arr2.length);