ABAP String Offset: Access, Extract, and Modify Substrings

Using Offset in SAP ABAP Strings

In SAP ABAP, you can use offsets to access or manipulate parts of a string by specifying a starting position and an optional length.

1. Accessing a Character at a Specific Offset

You can access a specific character in a string using an offset.

DATA: lv_string TYPE string VALUE 'HELLO ABAP',
      lv_char   TYPE c LENGTH 1.

lv_char = lv_string+6(1).  " Extracts the character at offset 6

WRITE: lv_char.  " Output: A

• Explanation:
• lv_string+6(1) extracts one character from the 7th position (offset starts at 0).
• The result is 'A' from "HELLO ABAP".

2. Extracting a Substring Using Offset and Length

You can extract a part of a string by specifying the offset (starting position) and length.

DATA: lv_string TYPE string VALUE 'HELLO ABAP',
      lv_substring TYPE string.

lv_substring = lv_string+6(4).  " Extracts 4 characters starting from position 6

WRITE: lv_substring.  " Output: ABAP

• Explanation:
• lv_string+6(4) extracts 4 characters starting from position 6, giving "ABAP".

3. Modifying a String Using Offset

You can modify specific parts of a string using an offset.

DATA: lv_string TYPE string VALUE 'HELLO ABAP'.

lv_string+6(4) = 'CODE'.  " Replace 'ABAP' with 'CODE'

WRITE: lv_string.  " Output: HELLO CODE

• Explanation:
• lv_string+6(4) = 'CODE' replaces 4 characters starting from position 6 with "CODE".

4. Using Offset in Loops to Process Characters

You can loop through a string using offsets.

DATA: lv_string TYPE string VALUE 'HELLO',
      lv_char   TYPE c LENGTH 1,
      lv_len    TYPE i.

lv_len = STRLEN( lv_string ).

DO lv_len TIMES.
  lv_char = lv_string+sy-index-1(1).  " Extract each character
  WRITE: / lv_char.
ENDDO.

• Explanation:
• Extracts and prints each character one by one using an offset.

5. Handling Dynamic Offsets (Avoiding Overflow)

If the offset is greater than the string length, ABAP will trigger a runtime error. You should check the string length before using an offset.

DATA: lv_string TYPE string VALUE 'ABAP',
      lv_length TYPE i.

lv_length = STRLEN( lv_string ).

IF lv_length >= 5.
  WRITE: lv_string+4(1).  " Safe access
ELSE.
  WRITE: 'Offset too large!'.
ENDIF.

• Explanation:
• The program checks if the string is long enough before extracting a character at offset 4.

Best Practices