Replace map for-each by classic for-loop?

December 22, 2021

Java 8

here some snippet:

String createSelector(Map.Entry<String, Map<String, String>> seriesMapEntry) {
   for (Map.Entry<String,String> column : seriesMapEntry.getValue().entrySet()) {
        String expr = column.getValue();
         // some code here
   }
}

Nice. It’s work fine.

Is it possible to iterate seriesMapEntry without for-each loop? E.g use classic for loop (iterate by index).

>Solution :

There is no index to iterate over. You can, however, use an explicit Iterator and a while loop:

String createSelector(Map.Entry<String, Map<String, String>> seriesMapEntry) {
   Iterator<Map.Entry<String,String>> iter = seriesMapEntry.getValue().entrySet().iterator();
   while (iter.hasNext ()) {
        Map.Entry<String,String> column = iter.next ();
        String expr = column.getValue();
         // some code here
   }
}