Java not getting the right condition

Question

I trying to get info in database and sending for an object called Question.

When i got null in database and send it to the field of the object.. I suppose that field will be "null", cause the field is an String.

But i tried all ways to verify it and i cant...

I tried:

    Question a = new Question();
    a.setAnswer(database.getAnswer(id));
    // Way 1
    if(a.getAnswer() == null) {
            Log.d("Way 1", "successfully");
    } 
    // Way 2
    if(a.getAnswer() == "null") {
            Log.d("Way 2", "successfully");
    }
    //Way 3
    if(a.getAnswer().equals(null)) {
            Log.d("Way 3", "successfully");
    }
    // Way 4
    if(a.getAnswer().equals("")) { 
            Log.d("Way 4", "successfully");
    }

But I didn't got result...

I put in log to log my Question.getAnswer() too:

And here's the result:

    D/Here == >: null

You are not comparing strings correctly in Way 2, use `equals` as you did in Way 4. — zozelfelfo, Feb 17 '14 at 16:18

score 0 · Answer 1 · answered Feb 17 '14 at 16:19

0

In Way 2

use : if(a.getAnswer().equals("null")( {

This is the way two strings must be compared.

answered Feb 17 '14 at 16:19

codingenious

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Naveed Yousaf · Answer 2 · 2014-02-17T17:34:45.407

0

Try this code for comparison

if(a.getAnswer().equals("")) {
    Log.d("Way 1", "successfully");
}

This will work as expected

edited Feb 17 '14 at 17:34

answered Feb 17 '14 at 16:23

Naveed Yousaf

133
2
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Maybe getAnswer returns already a `String` object, so in that case, it is not necessary to do that. – zozelfelfo Feb 17 '14 at 16:35
however, Naveed cannot be sure as he cannot see the declarations. this will ensure that `getAnswer` is always a `String`. – ylun.ca Feb 17 '14 at 16:51
@ylun you are right `getAnswer` will return string there is no need to convert string again to string. – Naveed Yousaf Feb 17 '14 at 17:34

Java not getting the right condition

2 Answers2