Get single item from List>

Question

I am modifying someone else code. I have a variable of type List<HashMap<String, String>>

List<HashMap<String, String>> lst

I tried to use get the item single value by using

lst[0,1]
lst[0][1]
lst.get(0)[1]
lst.get(0)(1)
lst.get(0)("ID")

but non works.

how to get a single item value?

    List<HashMap<String, String>> lst = null;

    try{
        lst = myXmlParser.detparse(reader);
    }catch(Exception e){
        Log.d("Exception", e.toString());
    }

use `list.get(index);` it will return you an object of type `HashMap` `index` here is an `int` of your choice. — SMR, Jul 07 '14 at 09:43
I used list.get(index) but it will not return a single value it will return a list of 4 items — asmgx, Jul 07 '14 at 09:46
possible duplicate of [Java: get specific ArrayList item](http://stackoverflow.com/questions/3920602/java-get-specific-arraylist-item) — SMR, Jul 07 '14 at 09:48
Not sure what the code producing the List> by getparse is meant to say in connection with the question "how to get a single item". — laune, Jul 07 '14 at 09:57

score 1 · Accepted Answer · answered Jul 07 '14 at 09:46

You should read the documentation of List and Map (respective HashMap) to see how to use them.

Since your List contains Map you'll have to get a Map using the List operations and then get the elements from that Map using the Map operations:

HashMap<String, String> firstMap = lst.get(0);
String someEntry = firstMap.get("key");

score 0 · Answer 2 · answered Jul 07 '14 at 09:43

0

HashMap<String, String> firstEntryInList = list.get(0);

Where '0' is the index.

answered Jul 07 '14 at 09:43

Stu Whyte

758
5
19

score 0 · Answer 3 · answered Jul 07 '14 at 09:45

0

Why not using index of list...

HashMap<String, String> entry = lst.get(0);

answered Jul 07 '14 at 09:45

Vinay Veluri

6,671
5
32
56

@DownVoter, Can it be commented, why to down vote? To return an element from a list using indexes - use get(index) is the suggestion and its appropriate to the question. – Vinay Veluri Jul 07 '14 at 09:59
I think that a rather weird one was downvoting each and every answer on this Q. I got credited +8, which looks like one up and one down, others may have experienced similar. – laune Jul 07 '14 at 11:00

score 0 · Answer 4 · answered Jul 07 '14 at 09:55

Accessor methods must be applied from outer to inner. If you have a

List<Whatever> lst

you use

lst.get(0)

to retrieve the first element in the list. If Whatever is in turn an aggregate, you apply the appropriate accessor on the returned value:

List<Map<String,String>> lst

and to get the string that's mapped via "somekey":

lst.get(0).get("somekey")

Now, this will get you a String, and this has accessors, too, eg. for accessing a single character:

lst.get(0).get("somekey").charAt(0)

This is "the first character of the string mapped with key "somekey" in the first hash map of the list lst".

Get single item from List>

4 Answers4