Table find number of matches

leclerke

I have a table with names in one column and I have to find out how many different names there are. Of course, double names only count once. I am totally not getting how to do this, though it shouldn'd be so hard :-S . Can anyone please help me?

Chrisir

Look at reference hashMap()

Chrisir

You can store a string in a hashMap and check if it's already in the hashMap

If I remember correctly you can say

HashMap<String, int> map = new HashMap ();

First try to read the int by giving in the string

If you receive null, string is new, add the string with int value 1

If you receive a value the string is already there. Read the int, add 1 and store back into the map

etc

Look at reference

kfrajer

You could sort the list and then iterate through the entries and count all of them that are different.

Kf

leclerke

Thank you, this is the easiest way I think!

Chrisir

count all of them that are different.

Store the previous entry and compare to it

Don't use == or != with strings

Use string.equals(a1)

koogs

You can store a string in a hashMap and check if it's already in the hashMap

if you don't need to remember the value part of the name / value pair then it's better to use a hashset, which just stores the key part.