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Version: 20 R7 BETA

COLLECTION TO ARRAY

COLLECTION TO ARRAY ( collection ; array {; propertyName}{; array2 ; propertyName2 ; ... ; arrayN ; propertyNameN} )

ParameterTypeDescription
collectionCollection→Collection to copy in array(s)
arrayArray←Array to receive the elements of the collection; if propertyName passed, array to receive the values of propertyName in the collection
propertyNameText→Object property name whose values to copy in array ("" for all elements)

Description​

The COLLECTION TO ARRAY command fills one or more array(s) with elements or propertyName values from the collection into the array(s).

This command can work with a collection that contains values or a collection that contains objects, in which case the propertyName parameter(s) are mandatory.

  • If you omit the propertyName parameter, the command copies all collection elements to array. After the command is executed, the size of array is identical to the collection length.
  • If you pass one or more propertyName(s) parameter, collection must be a collection of objects (other elements are ignored). In this case, each propertyName parameter indicates the name of a property within each object of the collection whose value(s) you want to copy in the corresponding array. You can pass any propertyName / array pairs you want, mixing array types. After the command is executed, each size of array is identical to the collection length.

In all cases, 4D converts the collection elements or values according to the type of array (if necessary). Conversion rules are detailed in the Type conversions between collections and 4D arrays page.

Example 1​

You want to copy a collection of strings in a text array:

 var $fruits : Collection
 $fruits:=New collection("Orange";"Banana";"Apple";"Grape")
 ARRAY TEXT($artFruits;0)
 COLLECTION TO ARRAY($fruits;$artFruits)
  //$artFruits{1}="Orange"
  //$artFruits{2}="Banana"
  //...

Example 2​

You want to copy different property values from a collection of objects in different arrays:

 var $col : Collection
 $col:=New collection
 ARRAY TEXT($city;0)
 ARRAY LONGINT($zipCode;0)
 $col.push(New object("name";"Cleveland";"zc";35049))
 $col.push(New object("name";"Blountsville";"zc";35031))
 $col.push(New object("name";"Adger";"zc";35006))
 $col.push(New object("name";"Clanton";"zc";35046))
 $col.push(New object("name";"Shelby";"zc";35143))
 
 COLLECTION TO ARRAY($col;$city;"name";$zipCode;"zc")
  //$city{1}="Cleveland", $zipCode{1}=35049
  //$city{2}="Blountsville", $zipCode{2}=35031
  //...

See also​

ARRAY TO COLLECTION
Type conversions between collections and 4D arrays