Can someone explain this line

Question

hello i'm trying ton understand a programm and a line giving me some trouble. Can you explain me the Construction of this line because i have never seen a "For" like that

for (Iterator<IBaseVO> itMachine = machinesSelected.iterator(); itMachine.hasNext();) {
            MachineVO mach = (MachineVO) itMachine.next();
            idsMachines.add(mach.getMchId());
        }

thanks you

`for (initialize itMachine; the condition itMachine.hasNext(); no incremental, just loop) {...}` — Cà phê đen, Jun 22 '17 at 08:40
Cause for statement have : for (initialization; termination; increment) { statement(s) } — Lemonov, Jun 22 '17 at 08:40

score 1 · Answer 1 · answered Jun 22 '17 at 08:43

1

A for loop can have 3 arguments, but it's not required.

Usually goes like this

instruction
boolean
instruction

the first and the third one can be omitted safely.

So here is the first instruction slot used to initialize the iterator object.

The second instruction slot is used to see if there are new items in the iterator.

the third slot is not needed and thusly omitted.

This does the same as

Iterator<IBaseVO> itMachine = machinesSelected.iterator();
while (itMachine.hasNext()) {
            MachineVO mach = (MachineVO) itMachine.next();
            idsMachines.add(mach.getMchId());
        }

answered Jun 22 '17 at 08:43

Tschallacka

27,901
14
88
133

"the first and the third one can be omitted safely." All three can be omitted. `for (;;) {}` is legal. – Andy Turner Jun 22 '17 at 08:49
I know it's legal, but it's not **safe** unless you bult in break; – Tschallacka Jun 22 '17 at 08:53
the presence of the expression doesn't immediately make it safe, though. `for(;true;) {}` is just as "unsafe". – Andy Turner Jun 22 '17 at 08:55

Can someone explain this line

1 Answers1