CASE TYPE OF - ABAP Keyword Documentation

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CASE TYPE OF

Syntax

CASE TYPE OF oref
  [WHEN TYPE class|intf [INTO target1].
    [statement_block1]]
  [WHEN TYPE class|intf [INTO target2].
    [statement_block2]]
  ...
  [WHEN OTHERS.
    [statement_blockn]]
ENDCASE.

Addition:

... INTO target

Effect

Special case distinction for object reference variables. This form of a control structure introduced using CASE checks the dynamic type of a non-initial object reference variable and the static type of an initial object reference variable oref. oref expects an object reference variable with the static type of a class or of an interface. oref is a general expression position.

A class class or an interface intf valid in this place must be specified after WHEN TYPE. The first statement block statement_block is executed for which the class class or the interface intf is more general than or equal to the

dynamic type of a non-initial object reference variable oref
static type of an initial object reference variable oref

If this does not apply to any class class or interface intf, the statement block is executed after WHEN OTHERS. No object type class or intf can be specified if it is possible to identify statically that it does not meet the condition.

Notes

A case distinction using CASE TYPE OF is a different spelling of the following branch using IF and the predicate expression IS INSTANCE OF and the corresponding rules and notes apply:

IF oref IS INSTANCE OF class|intf.
  [statement_block1]
ELSEIF oref IS INSTANCE OF class|intf.
  [statement_block2]
...
ELSE.
  [statement_blockn]
ENDIF.

The control structure must specify more specific classes class or interfaces intf before more general classes or interfaces to enable the associated statement block to be executed.

Example

See Case Distinction CASE TYPE OF for Exceptions.

Addition

... INTO target

Effect

For every statement WHEN TYPE of a case distinction introduced using CASE TYPE OF, a target variable target can be specified after the optional addition INTO as follows:

An existing object reference variable ref whose static type is more general or equal to the class class or interface intf specified in the statement.
An inline declaration DATA(ref). In this case, an object reference variable with the static type of the class class or the interface intf is declared.

If the addition INTO is specified in the first WHEN statement that meets the condition, the reference oref is assigned to ref before the statement block is executed. Here, both up casts and down casts can be performed.

Note

A statement

WHEN TYPE class|intf INTO ref.

is a semantically identically short form of

WHEN TYPE class|intf.
ref = oref.

A statement

WHEN TYPE class|intf INTO DATA(ref).

is a semantically identically short form of

WHEN TYPE class|intf.
DATA(ref) = CAST class|intf( oref ).

Example

See Case Distinction CASE TYPE OF for RTTI.

Continue
WHEN TYPE
Case Distinction CASE TYPE OF for Exceptions
Case Distinction CASE TYPE OF for RTTI