gistfile1.js

function reverseArray(items){
    var reversed = [];
    for(var i=items.length;i>0;i--){
      reversed.push(items.pop());
    }
    return reversed;
};
console.log(reverseArray(["A","B","C"]));

function reverseArrayInPlace(arrayItems){

    for(var i=0;i<arrayItems.length;i++){
        var tmp = arrayItems[i];
        arrayItems[i] = arrayItems[arrayItems.length-(i+1)];
        arrayItems[arrayItems.length-(i+1)] = tmp;
    }
};

var arrayItems = [1,2,3,4,5,6,7];
reverseArrayInPlace(arrayItems);
console.log(arrayItems);