How to compare two long value at runtime in java

Question

How to compare two long value at runtime. When I got the value of both of long type variable at runtime which same so it should be print else part but the both value is different from each other so it should be print if part.

Long dbData = 54188439.... // Got the value at run time
Long spreadSheet = 54188439.....//Got the value at run time

if(dbData != spreadSheet)
{
Log.i("","Please update your contact");
}
else
{
Log.i("","Not required");
}

Here I always got if part whatever be the condition. Please help me out.

You're comparing two different objects, whose contents just happen to be the same number — MadProgrammer, Aug 27 '15 at 06:22
have a look at [this](http://stackoverflow.com/a/20542511/1638708) - you're comparing Objects, not primitive `long` values — User42, Aug 27 '15 at 06:22
Nope I got the value of both variable at runtime. The value of both variable will anything. @MadProgrammer — abc, Aug 27 '15 at 06:23

Ankur Singhal · Answer 1 · 2015-08-27T06:40:27.893

1

Make use of equals operator

changed the statement from

if(dbData != spreadSheet)

to

  if(!dbData.equals(spreadSheet))

When Same

public static void main(String[] args) {
        Long dbData = new Long(54188439);
        Long spreadSheet = new Long(54188439);

        if (!dbData.equals(spreadSheet)) {
            System.out.println("Please update your contact");
        } else {
            System.out.println("Not required");
        }
    }

Output

Not required

When Different

public static void main(String[] args) {
     Long dbData = new Long(54188439);
    Long spreadSheet = new Long(541878439);

        if (!dbData.equals(spreadSheet)) {
            System.out.println("Please update your contact");
        } else {
            System.out.println("Not required");
        }
    }

output

Please update your contact

edited Aug 27 '15 at 06:40

answered Aug 27 '15 at 06:22

Ankur Singhal

26,012
16
82
116

In this condition, It also shows false condition @ankur-singhal – abc Aug 27 '15 at 06:25
@abc What do you mean by false condition? What it is printing? – Naman Gala Aug 27 '15 at 06:28
@abc i have edited the answer, see the output – Ankur Singhal Aug 27 '15 at 06:30
how I added `L` at runtime. In my condition it always showing 'Please update your contact' @ankur-singhal – abc Aug 27 '15 at 06:37
@abc `L` is something required when declaring. – Ankur Singhal Aug 27 '15 at 06:39
@abc can you show us how you are getting values at runtime? – Naman Gala Aug 27 '15 at 06:43

score 1 · Answer 2 · edited May 23 '17 at 12:22

1

The reason it won't work is because you are comparing the objects, not the values. See also https://stackoverflow.com/a/8968390/4890300 for a great answer.

edited May 23 '17 at 12:22

Community

1
1

answered Aug 27 '15 at 06:27

Marcus Demnert

88
6

This does not provide an answer to the question. To critique or request clarification from an author, leave a comment below their post. – Bruce Aug 27 '15 at 06:33
@Bruce actually it does answer the question. – Uma Kanth Aug 27 '15 at 07:41

score 0 · Answer 3 · answered Aug 27 '15 at 06:25

0

if(dbData.longValue() != spreadSheet.longValue())

Edit your condition as above. It will compare 2 long values. Your exiting condition compare 2 object references.

Thanks

answered Aug 27 '15 at 06:25

isurujay

1,386
10
15

score 0 · Answer 4 · answered Aug 27 '15 at 06:25

You should compare two instances of Long-class only with it's equals method, because == operators check the addresses, not the values.

if(!dbData.equals(spreadSheet)) 
{
  Log.i("","Please update your contact");
}
else
{
  Log.i("","Not required");
}

score 0 · Answer 5 · answered Aug 27 '15 at 06:26

0

Use Long.compare(long x, long y)

if (Long.compare(val1, val2) == 0) {
   // values are equal
} else {
   // values are not equal
}

answered Aug 27 '15 at 06:26

Raman Shrivastava

2,923
15
26

score 0 · Answer 6 · answered Aug 27 '15 at 06:26

Your dbData and spreadSheet are instances of the Long class, not long primitives. You have to compare theme either using the equals() method, or compare their longValue()s. I.e.

if (!dbData.equals(spreadSheet)) { 
  // ...
} else {
  // ...
}

or

if (dbData.longValue() != spreadSheet.longValue()) { 
  // ...
} else {
  // ...
}

score 0 · Answer 7 · answered Aug 27 '15 at 06:28

0

You can use below code.

    Long dbData = 54188439L;// Got the value at run time
    Long spreadSheet = 54188439L;//Got the value at run time

    if (!dbData.equals(spreadSheet)) {


    }

answered Aug 27 '15 at 06:28

Rafiq

740
1
5
17

How to compare two long value at runtime in java

7 Answers7