048-reverse-array.js

var arr = [1, 2, 3, 4, 5, 6, 7, 8]

for (var i=0; i < (arr.length / 2); i++) {
    var temp = arr[i]
    arr[i] = arr[arr.length -1 - i]
    arr[arr.length - 1 - i] = temp
}
console.log(arr);

//short cut
console.log("arr.reverse() : ",arr.reverse());