Get Example source ABAP code based on a different SAP table
ARTICLE
Type Checks and Type Compatibility Overview 1 Field symbols 2 STRUCTURE 3 LIKE ABAP Code Snippet
1 Field symbols If you define the types of field symbols using FIELD-SYMBOLS <(><)> STRUCTURE s DEFAULT wa and they are later assigned a data object wa using ASSIGN wa TO <(><)> ..., in non-Unicode programs both statements are checked to see that wa is at least as long as s and wa satisfies the alignment requirements of s at runtime.
2 STRUCTURE For historical reasons, field symbols and parameters of subroutines or Function modules can only be typed with the STRUCTURE addition. If, in a non-Unicode system, parameters in function modules or subroutines are typed with FORM form1 USING/CHANGING arg STRUCTURE s ... or FORM form2 TABLES itab_a STRUCTURE s ... and actual parameters are passed to them using PERFORM form1 USING/CHANGING wa or PERFORM form2 USING/CHANGING itab_b, the system also only checks whether wa or the row type of itab_b is at least as long as s and wa or whether the row type of itab_b meets the alignment requirements of s. The same applies to parameters of function modules that are typed using STRUCTURE. In Unicode programs, the following additional rules are checked after type assignments using STRUCTURE when assigning data objects - that is, for the DEFAULT addition to the FIELD-SYMBOLS statement, for ASSIGN, and when transferring actual parameters:
If wa or the row type of itab_b is a flat or deep structure, the Unicode fragment views of wa or itab_b must have the same length as that of s, including closing alignment gaps. The handling of closing alignment gaps is described in the section Data Layout of Structures.
If wa is a single field, only the character-type types C, N, D, or T are allowed and the structure s must be purely character-type.
3 LIKE If, in non-Unicode programs, the type of an argument in a function module was defined using ... LIKE struc, where struc is a flat structure, the system only checks whether the argument is a flat structure with the same length during parameter transfer. In Unicode programs, it also checks whether the fragment views of the current and formal parameters match.
ABAP Code Snippet Furthermore, two structures of which one or both contain ABAP Code Snippet alignment gaps caused by the Include are the same on all platforms. In the following example, struc1 and struc2 are not compatible because a further alignment gap occurs in the Unicode system ABAP Code Snippet BEGIN OF struc1, BEGIN OF struc2, BEGIN OF struc3, a(1) TYPE X, a(1) TYPE X., b(1) TYPE X, ABAP Code Snippet c(1) TYPE C, END OF struc2. END OF struc3. END OF struc1. Since the type compatibility can differ in a Unicode program and an non-Unicode program, the type compatibility rules of the calling program are valid for checking the parameters in a non-Unicode system. Therefore, if a non-Unicode program calls a Unicode program, the type compatibility is defined as in the non-Unicode program. Conversely, the Unicode check is activated if a Unicode program calls a non-Unicode program.
