Question

I have this (sub)object called products.original.

which I then extract to a new object called productArray:

var productArray = [];

productArray = products.original;

/*some calculations here*/

//sort the object by lowest score
productArray.sort(function(a, b) {return a.score - b.score;});

Finally, I extract the first three cells in productArray to a third object called resultArray:

var resultArray= [];        
resultArray = productArray.splice(0,3);

To my surprise, this reduces the length of products.original by 3 (the splice). Why? And what do I do to hinder this? Thanks in advance.

Answer 1

You did not copy the array, but just the reference to it. So all your operations are still performed on the original object.
For real cloning use slice.

 productArray = products.original.slice(0);