Sometimes, when you assign or pass an ABL primitive type to a .NET property or when you pass an ABL primitive type to a .NET method parameter, and more than one .NET type mapping is possible, you must explicitly indicate the mapping you want. You might also need to indicate the explicit .NET type when you assign (and box) an ABL primitive type to a System.Object or when you pass the ABL primitive as an argument to a System.Object or overloaded .NET method parameter. You must indicate explicit .NET data types when you define an ABL method or property in order to override a .NET method or implement a .NET interface (see the C# .NET code mapped to OpenEdge GUI for .NET ABL C# .NET code mapped to OpenEdge GUI for .NET ABL

For a .NET mapped type that is the default or only match for a given ABL data type, you only use the ABL data type to explicitly indicate the .NET type mapping. For all other .NET mapped types, ABL provides a special type keyword (ABL AS data type) that indicates the explicit .NET type mapping. The following table shows all the mappings between ABL and .NET primitive types as well as the AS data type keyword that you can use to indicate the explicit mapping to a .NET type other than the default match for the ABL primitive type.

Table 1. Explicit data type mapping from ABL primitive to .NET types
Explicit .NETobject type Explicit C#primitive type ABLprimitive type ABLAS data type
System.Boolean bool LOGICAL —
System.Byte byte INTEGER UNSIGNED-BYTE
System.SByte sbyte INTEGER BYTE
System.DateTime — DATETIME —
System.Decimal decimal DECIMAL —
System.Int16 short INTEGER SHORT
System.UInt16 ushort INTEGER UNSIGNED-SHORT
System.Int32 int INTEGER —
System.UInt32 uint INT64 UNSIGNED-INTEGER
System.Int64 long INT64 —
System.UInt64 ulong DECIMAL UNSIGNED-INT64
System.Double double DECIMAL DOUBLE
System.Single float DECIMAL FLOAT
System.Char char CHARACTER SINGLE-CHARACTER
System.String string CHARACTER/ LONGCHAR —

The following table shows examples of an explicit .NET type mapping using the AS data type keyword.

Table 2. Example explicit data type mappings using the AS data type keyword
Operation description Operation with Type of data element
Assign an INTEGER as a System.Int16 value to a System.Object property or variable (creating a new System.Int16 object in the process). System.Object = BOX( INTEGER, "SHORT").
Pass an INTEGER as a System.Int16 argument to the System.Object parameter of a .NET method (creating a new System.Int16 object in the process). Method( INPUT INTEGER AS SHORT ).