For each loop

[Roel De Nijs]

(Question Java Tiger)

 
HashMap<String, TestA> kolommen = ...;
for (DBKolom kolom : [B]kolommen.values()[/B])
str.append(kolom + "\n"); 

concern the code in bold: i guess the method values() is executed once (at the beginning of the loop) and not every time a new value is assigned to variable kolom, because that would be a performance problem

[Steve Morrow]

Values is only called once (in order to get at an Iterator).

[Barry Gaunt]

The values() method returns a Collection, and to iterate through that collection an Iterator is obtained from kolommen.values().iterator(). That's done only once, exactly as in the first part of a normal for loop:

for (Iterator i = kolommen.values().iterator(); ... ; ... ) {
    // code
}

[Roel De Nijs]

Originally posted by Barry Gaunt:
The values() method returns a Collection, and to iterate through that collection an Iterator is obtained from kolommen.values().iterator(). That's done only once, exactly as in the first part of a normal for loop:

for (Iterator i = kolommen.values().iterator(); ... ; ... ) {
    // code
}

that's exactly what my .class file looks like after i decompiled it (i thought too late about that option to verify my ideas (it's almost weekend so the brain is slowing down )