Increments the iterator of a
For...Next loop
Syntax
Usage
For iterator [ As typename ] = start_value To end_value [ Step step_value ]
[ ...statements... ]
Next
Parameters
typename
stp,
step_value
a typename object used as an incremental value
iterator
a typename object used as an iterator
end_value
a typename object used as a loop-terminating value
start_value
a typename object used to copy construct or assign to the iterator initially
Description
Operator For,
Operator Next and
Operator Step can be overloaded in user-defined type definitions to allow objects of that type to be used as iterators and step values in
For...Next loops.
Operator Step is called to increment the iterator immediately after all statements in the
For...Next body are executed, if any.
The first version of
Operator Step is used if no step value is given in the
For...Next statement. If a step value is given, the second version is used and is passed the step value.
Example
'' Example Type
Type T
value As Double
Declare Constructor( ByVal x As Double = 0 )
Declare Operator += ( ByVal x As Double )
Declare Operator For( ByRef stp As T )
Declare Operator Step( ByRef stp As T )
Declare Operator Next( ByRef cond As T, ByRef stp As T ) As Integer
Declare Operator Cast() As String
End Type
Constructor T ( ByVal x As Double )
value = x
End Constructor
Operator <= ( ByRef lhs As T, ByRef rhs As T ) As Integer
Operator = ( lhs.value <= rhs.value )
End Operator
Operator >= ( ByRef lhs As T, ByRef rhs As T ) As Integer
Operator = ( lhs.value >= rhs.value )
End Operator
Operator T.+= ( ByVal x As Double )
value += x
End Operator
Operator T.for( ByRef stp As T )
End Operator
Operator T.step( ByRef stp As T )
This += stp.value
End Operator
Operator T.next( ByRef cond As T, ByRef stp As T ) As Integer
If( stp.value < 0 ) Then
Operator = ( This >= cond )
Else
Operator = ( This <= cond )
End If
End Operator
Operator T.cast() As String
Operator = Str( value )
End Operator
'' Example Usage
For i As T = 10 To 1 Step -1
Print i
Next i
Dialect Differences
See also