To break loops, the command
EXIT can be used.
DO. READ TABLE itab INDEX sy-index INTO DATA(wa). IF sy-subrc <> 0. EXIT. "Stop this loop if no element was found ENDIF. " some code ENDDO.
To skip to the next loop step, the command
CONTINUE can be used.
DO. IF sy-index MOD 1 = 0. CONTINUE. " continue to next even index ENDIF. " some code ENDDO.
CHECK statement is a
CONTINUE with condition. If the condition turns out to be false,
CONTINUE will be executed. In other words: The loop will only carry on with the step if the condition is true.
This example of
DO. " some code CHECK sy-index < 10. " some code ENDDO.
... is equivalent to ...
DO. " some code IF sy-index >= 10. CONTINUE. ENDIF. " some code ENDDO.