What is the best way to iterate through a HashMap?
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i want to retrieve k,v-pairs from a hashmap.
the entrys are like this:
a = 3,4
b = 5,6
and so on. i need combinations of these values.
a=3, b=5.
a=3, b=6.
a=4, b=5.
a=4, b=6.
I don't ... |
Iterator<Player> iterator = plugin.inreview.keySet().iterator();
while (iterator.hasNext()) {
Player key = (Player) iterator.next();
chat.getRecipients().remove(key);
}
This throws an: java.util.NoSuchElementException
at java.util.HashMap$HashIterator.nextEntry(Unknown Source)
at java.util.HashMap$EntryIterator.next(Unknown Source)
at java.util.HashMap$EntryIterator.next(Unknown Source)
Any ideas as to why ... |
Java Programming
Issues With Iterating My Map
Iterator<Player> iterator = plugin.inreview.keySet().iterator();
while (iterator.hasNext()) {
Player key = (Player) iterator.next();
chat.getRecipients().remove(key);
}
This throws:
java.util.NoSuchElementException
at java.util.HashMap$HashIterator.nextEntry(Unknown Source)
...
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im writing a program that parses data from a log file. each line in the log is either a process wit a start time or an end time for one of the started processes. i already figured out how to print all the start times but i cant wrap my head around how to pull out the end time for each ... |
the following code DelMeObject o1 = new DelMeObject("o-n-e"); DelMeObject o2 = new DelMeObject("t-w-o"); DelMeObject o3 = new DelMeObject("t-h-r-e-e"); HashMap hm = new HashMap(); hm.put("1",o1); hm.put("2",o2); hm.put("3",o3); Iterator myVeryOwnIterator = hm.keySet().iterator(); while(myVeryOwnIterator.hasNext()) { String s = (String)myVeryOwnIterator.next(); System.out.print(s+"..."); DelMeObject temp = hm.get(s); System.out.println(temp); } gives me output 3...object name t-h-r-e-e 2...object name t-w-o 1...object name o-n-e but what i want is 1...object ... |
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I hava 2 hashmaps..the entrySet for first is like [a=10, b=20, c=30] and that for the second is [a1=2, b1=4, c1=3]... Now I want to add the values of first map i.e 10+20+30... and add the values of second i.e 2+4+3... And my final desired output is (10+20+30)/(2+4+3).... Now how to get it done using these 2 hashmaps...meaning how to iterate ... |
What variable is null that is causing the exception? Copy and paste the full text of your error message here. If there is a reference to a line number in your program, copy and comment the lines surrounding the line noted with the error. Use the javac -g option to include line numbers in the class file. [ July 14, 2008: ... |
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Hi, I am trying to iterate over two the hashMaps where I need the combination of elements from both the hashMaps. The iteration must be something similar to bubble Sort for(int i=0; i str1 = st1.nextToken(); for(int j=i+1; j |
I seem to have a brain block - after some hours of trying, reading, googling I haven't find the solution yet for a problem which is surely quite simple. I want to iterate through a HashMap. The relevant code in my class is like follows: private HashMap Tix; void WriteATix (File f) { Iterator it = Tix.entrySet().iterator(); while (it.hasNext()) { ... |
hi out there. i read a textfile, fiddle with it and store values into a hashmap: HashMap metadata = new HashMap(); what i want is every combination from the input-file-data. let's say the file is: generic a=1,3 generic b=2,4 then output should be a=1, b=2; a=1, b=4; a=3, b=2; a=3, b=4. i don't know how many keys the map ... |
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Does the iterator interface define any methods that allow you to go backwards? Or to "reset" it? No. It has the methods "hasNext", "next", and "remove". Which one of those three methods indicates to you that the Iterator can be reused? Simply get another one from the HashMap (like uncommenting that commented line). |
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I would take a look at the Collections framework here: http://java.sun.com/j2se/1.4.2/docs/guide/collections/reference.html So two things: 1.) You'll probably just want to use iterator.hasNext() in a while loop to get everything out of the Iterator object and into your reasonsList. 2.) If I understand correctly, that's still just going to get you the values (not the keys). In which case you could do: ... |
Hi, I am trying to figure out how to iterate over a HashMap with keys that are Strings and values that are nodes with multiple fields. I have information on each node (name, xy position, label, etc) and was wondering how I parse through that information when I want to iterate over specific fields of each node value of the HashMap? ... |
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Hi, Can some one please tell me how can I iterate through a HashMap that may contain some more HashMaps and they inturn may contain more HashMaps and so on. How can I iterate throught all the HashMaps recursively in order i.e. First HashMap finds a HashMap iterate through that and if that finds another HashMap them iterate through that first ... |
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