Automatic and Non-Automatic Conversions

An automatic conversion lets the compiler change a data type automatically. No special syntax is necessary. In the example that follows, ViviFire automatically changes the value of k to a floating-point value, then assigns that to q.

Dim k As Int32
Dim q As Real64
' Int32 widens to Real64
k = 321
q = k

A non-automatic conversion uses an operator to change a data type to a different one. ViviFire supplies two such operators, As and In, which change an expression to the necessary data type.

The example below continues from the example before. The value of q is changed to Int32, then assigned to k.

' q has the value 321.
q = Math.Sqrt(q)
k = q As Int32
' k has the value 18 (rounded square root of 321).

As operator

Initial type Can change to
A numeric type1 All numeric types, String, object2
Boolean All numeric types, String, object
Char, array of Char String
An object type All data types3
String All numeric types, Char, DateTime, object
  1. Int8, UInt8, Int16, UInt16, Int32, UInt32, Int64, UInt64, Int128, UInt128, Real32, Real64, Real128
  2. Must have a type conversion constructor.
  3. Must have a type conversion method.

In operator

The operator In can change a numeric expression to a unit of measure. If the expression is a unit of measure, it can change it to a different unit from the same base unit. All units of measure are stored as floating-point types.

See also