For In Array/Collection command

Scans a unidimensional or multidimensional array or a structured data type collection.

Syntax

For &Var in &Variable()
    code
Endfor

Where:

&Var
     Specifies a variable that must have the same data type of the Array().

&Variable()
     Details a variable based on an array of one or more dimensions, or a structured data type collection.

Scope

Objects: Procedure, Transaction, Web Panel
Generators: .NET, .NET Framework, Java, RPG, Cobol, Ruby (up to GeneXus X Evolution 3)

Description

This command allows you to process or scan any array or structured data type collection variable.

Notes:

• It is not possible to modify the array values in the scanning. This means that changes in the &Var value, in the structure scope, do not affect the corresponding Variable value or vice versa.
• It is not possible to obtain the vector position during the scanning. This is possible if a variable as a counter is defined.
• It is possible to nest these structures to scan several Variables (arrays or collections). This takes into account when a Subroutine, that also has a For In &Variable, is called within the structure.
• Like in For Each command or Do While, it is possible to include commands that "break" the scanning, such as Exit command or Return command.

Samples

The following code belongs to a unidimensional array. It stores each value of the array in the &Var variable

for &var in &arr()
   … // code
endfor 

In case of one-dimensional vectors, the code is expanded to:

&x = 1
Do while &x <= rows(&arr())
   &var = &array(&x)
    ... // code
   &x += 1
Enddo  

In case of two-dimensional arrays, the command is analog:

for &var in &arr2()
   … // code
endfor

With &arr2, the expanded code would be:

&x = 1
Do while &x <= rows(&arr2())
   &y = 1
    Do while &y <= cols(&arr2())
       &var = &arr2( &x, &y)
        ... // code
       &y += 1
    Enddo
    &x += 1
Enddo

In case of an SDT collection:

The code would be:

for &item in &collection
  … 
endfor

With &collection is a variable based on “SDT01” Structure Data type collection, and &item is based on “SDT01.SDT01Item” type.

The expanded code would be:

&x = 1
Do while &x <= &collection.count
   &item.Itm1 = &collection.item(&x).Itm1
   &item.Itm2 = &collection.item(&x).Itm2
   ... // code
   &x += 1
Enddo

See Also

Do While Command