Get Index of a row using line_index ABAP 7.4

In NetWeaver 7.4, getting the index of a row in an internal table is simple with a table expression line_index , it will return index number of the row, if row does not exist, it will return 0

SYNTAX: <lv_index> = line_index( <ITAB> [ <COLUMN1> = <VALUE> <COLUMN2> = <VALUE> ... ] ).

Example using line_index SAP ABAP 7.4

With Single condition

SELECT *
  FROM MARA
  INTO TABLE @DATA(IT_MARA)
  UP TO 50 ROWS
  WHERE MTART = 'FERT'.

  DATA(lv_index) = line_index( it_mara[ matnr = '0001' ] ).
  IF lv_index > 0. "Line exists 
  WRITE:/ lv_index.
  ENDIF.

With multiple conditions

SELECT *
  FROM MARA
  INTO TABLE @DATA(IT_MARA)
  UP TO 50 ROWS
  WHERE MTART = 'FERT'.

  DATA(lv_index) = line_index( it_mara[ matnr = '0001' matkl = '0001' ] ).
  IF lv_index > 0. "Line exists 
  WRITE:/ lv_index.
  ENDIF.