Java遍歴の多様な書き方
1232 ワード
JDK1.4
Map map = new HashMap() ; Iterator it = map.entrySet().iterator() ; while (it.hasNext()) { Map.Entry entry = (Map.Entry) it.next() ; Object key = entry.getKey() ; Object value = entry.getValue() ; }
JDK1.5
Map m = new HashMap(); for (Object o : map.keySet()) { map.get(o); }
Map map = new HashMap() ; Iterator it = map.entrySet().iterator() ; while (it.hasNext()) { Map.Entry entry = (Map.Entry) it.next() ; Object key = entry.getKey() ; Object value = entry.getValue() ; }
JDK1.5
Map m = new HashMap(); for (Object o : map.keySet()) { map.get(o); }
// For a set or list
for (Iterator it=collection.iterator(); it.hasNext(); ) {
Object element = it.next();
}
// For keys of a map
for (Iterator it=map.keySet().iterator(); it.hasNext(); ) {
Object key = it.next();
}
// For values of a map
for (Iterator it=map.values().iterator(); it.hasNext(); ) {
Object value = it.next();
}
// For both the keys and values of a map
for (Iterator it=map.entrySet().iterator(); it.hasNext(); ) {
Map.Entry entry = (Map.Entry)it.next();
Object key = entry.getKey();
Object value = entry.getValue();
}