Using Maximum and Minimum Values of System Types

Article number: KB000007

General Information

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Description

When analyzing application code it was found that custom values are used to mark limits of minimum value. This may lead to obtaining wrong results when executing a function similar to the function described below:

Public Function min_r(q: Array Of Double): Variant;
Var
    min: Double;
    i: Integer;
Begin
    min := -99999999;
    For i := 0 To q.Length - 1 Do
        If q[i] > min Then
            min := q[i];
        End If;
    End For;
    Return min;
End Function min_r;

Use the MinValue and MaxValue properties to get minimum or maximum values for various types of data:

Minimum value of data type	Maximum value of data type
Currency	Currency
DateTime	DateTime
Decimal	Decimal
Double	Double
Integer	Integer
TimeSpan	TimeSpan

Example

Correct method of specifying limits of the minimum value:

Public Function min_r(q: Array Of Double): Variant;
Var
    min: Double;
    i: Integer;
Begin
    min := Double.MinValue;
    For i := 0 To q.Length - 1 Do
        If q[i] > min Then
            min := q[i];
        End If;
    End For;
    Return min;
End Function min_r;