Select-case

有人能说下这个多重判断语句是怎么执行的么Select-case

macro_command main()
bool on=1
short A
GetData(A, "Local HMI", LW, 0, 1)
select case A
case 1
SetData(on, "Local HMI", LB, 1, 1)
break
case 2
SetData(on, "Local HMI", LB, 2, 1)
break
case 3
SetData(on, "Local HMI", LB, 3, 1)
break
case 4
SetData(on, "Local HMI", LB, 4, 1)
break
case 5
SetData(on, "Local HMI", LB, 5, 1)
break
end select

end macro_command


当LW0寄存器中的值为1时，把LB1置ON；值为2时，把LB2置为ON……值为5时，把LB5置为ON。