Collection Classes In AX 2012

        We cannot store objects in arrays (x++ class) or containers. The Microsoft Dynamics AX collection classes have been designed for storing objects.  

Collection classes were formerly called Foundation classes. 

Below are collection classes 

• * Set  

• * Map  

• * List  

• * Array 

• * Struct 

Set:

• * Set Holds the value of any single type. 

• * Values are not stored in the sequence they are added. Instead, the Set object stores them in a *        manner that optimizes performance for the in method. 

• * It will not Allow the Duplicate Values. 

• * To overcome the limitations of list We use Set. 

• * It has Add method. 

• 
  

Example: 

static void set(Args _args) 

{  

  // Create a new set of type integer 

    Set s= new Set (Types::Integer); 

    SetEnumerator setenum;  

// Add elements to the set 

    s.add( 20); 

    s.add( 25); 

    s.add( 20); 

// Get the enumerator of the set 

// to loop through it 

    setenum= s.getEnumerator(); 

    While (setenum.movenext()) 

    { 

        Info (strfmt('Value is: %1 ',setenum.current())); 

    } 

} 

Map: 

• * Map Associates a key value with another value. 

• * It doesn't allow duplicate Key values in Maps. 

• * Maps sorted  based on Key Value. 

• * It has an Insert Method. 

• 
  

Example: 

static void Map(Args _args) 

{ 

    Map demomap; 

    MapEnumerator enumerator; 

  // Creating a map of Valuetype is string and key value is integer 

    demomap = new Map(Types::String, Types::Integer); 

   // Adding Elements To the Map 

    demomap.insert("jaipal", 1); 

    demomap.insert("jadav", 2); 

   //Get the Enumerator For Map  

    // for looping the all elements 

    enumerator = mapTest.getEnumerator(); 

    while (enumerator.moveNext()) 

    { 

        info(strfmt("Key - %1 , Value  %2.",enumerator.currentKey(),enumerator.currentValue())); 

    } 

} 

• We can also use Iterators for looping but here we are using Enumerators. 
   

• Iterators replaced because of  a few unwarranted drawbacks that appear as hard-to-find errors. 

List: 

• * It will hold similar datatype. 

• * It retrieves the the way we  are given 

• * It allows the duplicate values. 

• * List class provides an addStart method, and AddEnd method. 

• 
  

Example: 

static void Collection_List() 

{ 

// Create a new list of type string 

List names = new List(Types::String); 

ListEnumerator  listE; 

// Add elements to the list 

names.addEnd("jaipal"); 

names.addEnd("jadav"); 

names.addStart("Srikanth"); 

// Get the enumerator of the list 

// to loop through it 

listE = names.getEnumerator(); 

while (listE.moveNext()) 

{ 

info (strfmt("Name: %1", listE.current())); 

} 

} 

Struct:  

A struct holds several values of any X++ type, to group the information about a specific entity. 

Example: 

static void Collection_Struct() 

{ 

// Create a struct with two fields 

struct myCar = new struct (“int ModelYear; str Carbrand”); 

int i; 

; 

// Set values to the fields 

myCar.value(“ModelYear”, 2015); 

myCar.value(“Carbrand”, “BMW”); 

// Add a new field and give it a value 

myCar.add(“Model”, “320”); 

// Loop through the fields of the struct 

for (i=1; i<=myCar.fields(); i++) 

{ 

info(strfmt(“FieldType: %1, FieldName: %2, Value: %3”, 

myCar.fieldType(i), 

myCar.fieldName(i), 

myCar.value(myCar.fieldName(i)))); 

} 

}