Whenever you need a data locally to a block because it doesn't goes into a class attribute or reference, you can use a local variable.

A variable is defined by a name and by a type. If needed, the name of the variable can be escaped using the tilda (~)

Declaring a variable:

var foo : String // This is a variable declaration

In the following example, we define 3 variables of type integer. The first is initialized with the "14" literal value, the second is initialized with an expression using v1. For the last variable, we use a multiplicity notation to specify an ordered set of integer (see Section 2.15, “ Collections ” and Section 2.16, “ Class properties ” for more information on sets).

do
    var v1 : Integer init 14
    var v2 : Integer init 145 * v1

    var tab : Integer[0..*] init kermeta::standard::OrderedSet<Integer>.new
    v1 := v2/v1
end

Be careful to the multiplicity, when you create a variable with multiplicity, you have to initialize it with a collection . Then to use its content, you need to use the collection operation like add, addAll, remove, select, etc. If you use the assignment := it will replace your collection.