CODEWITHSUNDEEP
c#variablesglobal-variables
Ben
Ben

Reputation: 2715

C# variable value being assigned incorrectly issue

I have written a method with the idea of keeping a certain variable in memory in order to optimize the program. The issue i'm having is that in the variable previousSearchInfoForSavingsseems to always be the same as searchInfo even though it shouldn't be as it is only assigned in certain places.

The idea is that if you pass in the same searchInfo array it will recognise that it is the same as previousSearchInfoForSavings and not run the ClearPageNavigation.main method.

However this does not seem to be the case. If different values are passed in for searchInfo it doesn't seem to matter and and previousSearchInfoForSavingsseems to automatically update to these values.

For example:

If I pass in {"X","Y","Z"} in as searchInfo the first time previousSearchInfoForSavings is null so it will enter that if statement. This is fine. The next time if I pass in {"A","B","C"} at the beginning (where the comments are) these arrays are already equal. This should not be the case.

My code:

private static TableRow[] TRforSavings = null;
private static string[] previousSearchInfoForSavings = null;

public static bool[] main(
    string[] searchInfo,
    string[] compareInfo,
    string ClearFinancesTestPageURL
) {             
    if (searchInfo[1] == "Savings") {
        //searchInfo == previousSearchInfoForSavings here 
         bool[] results;
         if (previousSearchInfoForSavings == null) {
             previousSearchInfoForSavings = searchInfo;
             TableRow[] TR = ClearPageNavigation.main(
                  ClearFinancesTestPageURL,
                  searchInfo[0],
                  searchInfo[1],
                  searchInfo[2],
                  searchInfo[3]
             );
             results = CompareSavings.main(TR, compareInfo);
             TRforSavings = TR;
         } else {
             if (ArraysEqual(previousSearchInfoForSavings, searchInfo)) {
                 results = CompareSavings.main(TRforSavings, compareInfo);
             } else {
                 TableRow[] TR = ClearPageNavigation.main(
                     ClearFinancesTestPageURL,
                     searchInfo[0],
                     searchInfo[1],
                     searchInfo[2],
                     searchInfo[3]
                 );
                 results = CompareSavings.main(TR, compareInfo);
                 TRforSavings = TR;
                 previousSearchInfoForSavings = searchInfo;
            }
        }
        //searchInfo == previousSearchInfoForSavings here
        return results;
    }
}

Any ideas?

Upvotes: 0

Views: 137

Answers (2)

brz
brz

Reputation: 6016

This problem happens because you are assigning previousSearchInfoForSavings = searchInfo and thus copying searchInfo's reference in your local variable. And I suspect that you are sending the same searchInfo into your main method with changed values and that's why array elements change in both instances. To avoid this you have to copy searchInfo elements into previousSearchInfoForSavings instead of assigning.

Upvotes: 0

heathesh
heathesh

Reputation: 1031

The problem is that you're using reference types, and you should be cloning "searchInfo" instead of setting "previousSearchInfoForSavings" to be equal to it. So instead of:

previousSearchInfoForSavings = searchInfo;

You should be doing something like:

previousSearchInfoForSavings = (string[])searchInfo.Clone();

Upvotes: 3

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