Problems with ArrayList> and IF-STATEMENT

Question

I have a Array List with HashMap

deviceDataCollection = new ArrayList<HashMap<String,String>>();

I have to retrieve some data from this Array e compare using an IF-STATMENT, like the code below:

String DeviceType = deviceDataCollection.get(position).get("var").toString();
//it returns a string: lamp 

if (DeviceType == "lamp")
{
       // do something
}

The problem is: I can't get enter the IF-STATEMENT. I'm sure the values are exact the same.

I don't know what to do.

Thanks.

Refer to my [answer](http://stackoverflow.com/a/16329952/2024761) here! `if ("lamp".equals(DeviceType))` is what you need! — Rahul, May 02 '13 at 03:48

score 0 · Answer 1 · answered May 02 '13 at 03:49

0

When comparing Strings use equals()

So in your conditional it should be DeviceType.equals("lamp")

answered May 02 '13 at 03:49

shyamal

826
10
16

score 0 · Answer 2 · answered May 02 '13 at 03:49

0

When you compare reference types in Java (and Android) you need to use the .equals() method:

if (DeviceType.equals("lamp"))
{
       // do something
}

== determines equality by when something is in memory, .equals() will consider its value.

answered May 02 '13 at 03:49

Hunter McMillen

59,865
24
119
170

score 0 · Accepted Answer · answered May 02 '13 at 03:50

0

Use equals("lamp") or equalsIgnoreCase("lamp") method to co0mpare two Strings.

if (DeviceType .equals("lamp"))
 {
   // do something
  }

answered May 02 '13 at 03:50

Deepak

327
1
7

Thanks. It has worked perfectly. – user2341575 May 02 '13 at 15:58
@user2341575 did you just vote and unvote? – Raghunandan May 02 '13 at 16:04

Raghunandan · Answer 4 · 2013-05-02T03:59:30.837

Use

    if ("lamp".equals(DeviceType))
    {
             //do something
    }

The operator, ==, tests to see if two object reference variables refer to the exact same instance of an object.

The method, .equals(), tests to see if the two objects being compared to each other are equivalent -- but they need not be the exact same instance of the same object.

http://docs.oracle.com/javase/7/docs/api/java/lang/Object.html

Check the equals method in the link above

score 0 · Answer 5 · answered May 02 '13 at 03:55

0

Try this:

if (DeviceType.equals("lamp"))
{
   // do something
}

Strings are compared using equals function and not ==.

answered May 02 '13 at 03:55

Mihir Shah

996
10
19

Problems with ArrayList> and IF-STATEMENT

5 Answers5