Problem with sorting array algorithm

I have three arrays. And I am trying to sort all of them by one of them so. So my arrays are itemarray, pricearray, quantityarray. I want itemarray to be sorted but the corresponding arrays aren't sorting appropriately along with itemarray.

Here is the algorithm I created. Do you know how I can fix this??

DO i=1, NumItems-1

    SmallestItem = MINVAL(itemarray(i:NumItems))
    MINLOC_array = MINLOC(itemarray(i:NumItems))
    Locationsmallest = (i-1)+MINLOC_array(1)

    itemarray(Locationsmallest) = itemarray(i)
    itemarray(i) = SmallestItem

    pricearray(Locationsmallest) = pricearray(i)
    pricearray(i) = SmallestItem

    quantityarray开发者_开发知识库(Locationsmallest) = quantityarray(i)
    quantityarray(i) = SmallestItem

END DO  

You are setting pricearray(i) to something that came from itemarray. You should be swapping pricearray(Locationsmallest) and pricearray(i), which you can do by storing the value of pricearray(Locationsmallest) in a temporary variable.

The same is true for quantityarray(i).

By the way, this is an O(n^2) algorithm, and is likely to be very slow when there are a large number of values in your array.