Making an independent copy of a reversed array in JavaScript

Question

Here is my fiddle: http://jsfiddle.net/sepoto/Zgu9J/1/

I\'m starting with a reverse function:

function reverseArr(input) {
    var ret = new Array;
          


        

Answer 1

Your function is working correctly, even if it could be abbreviated to

return input.slice().reverse();

---

//This will show that pointOrigins2 is not an independent copy of pointOrigins1
//When pointOrigins2 is modified pointOrigins1 is also being modified
pointOrigins2[0].index++;

No. You are not modifying the pointOrigins2 array here, you are only accessing it and modifying the point object - the same point that was in the pointOrigins1 array. Yet, pointOrigins1 !== pointOrigins2.

You can modify the array independent from the other, e.g. like

pointOrigins2[0] = {
    positionx: pointOrigins2[0].positionx, 
    positiony: pointOrigins2[0].positiony, 
    index:     pointOrigins2[0].index + 1
};

and pointOrigins1 will stay untouched. So if you want to have points whose properties you can modify without being reflected somewhere else, you will need to create new points.