null check with Date object

Question

My method takes a Date object. And I am passing a null value.How can I check if the (Date date) date is null or not.I am new in Stackoverflow, If the question is not a good one please don't undergrade the post.

@AndreasFester That other Question is more about the Bitwise OR operator than it is about testing for Null. — Basil Bourque, Jan 22 '16 at 20:08
@BasilBourque Thats true - it should nevertheless give some hint on how to do a null check in general. A better answer is probably at http://stackoverflow.com/questions/21664478/java-object-null-check-for-method. But there are now also many specific answers to OP's concrete question below ;-) — Andreas Fester, Jan 22 '16 at 20:24

score 17 · Answer 1 · answered Jan 22 '16 at 10:18

17

Check if it is null:

if (date == null) {...}

Check if it is not null:

if (date != null) {...}

answered Jan 22 '16 at 10:18

James

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Tip: Putting the null on the left side helps to avoid accidentally using a single `=` thereby making an assignment rather than a test. Like this: `if ( null == date )` and `if( null != date )`. Also, the null on the left may be easier to read as your brain instantly knows you are doing a null test of something. – Basil Bourque Jan 22 '16 at 20:11

score 2 · Answer 2 · answered Jan 22 '16 at 10:33

2

In Java 8 you could use an Optional<Date> and check its empty() or isPresent() methods.

answered Jan 22 '16 at 10:33

Aaron

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score -1 · Answer 3 · answered Jan 22 '16 at 11:52

Java Code : Check if date is null

    public static void main( String[] args )
        {           
            Date date = showDate();
            //check with if-else statement with equals()
            if ( !date.equals( null ) )
            {
                System.out.println( "hi" );
            }
            else
            {
                System.out.println( "hello" );
            }
            //check with if-else statement with = oprator
            if ( date!= null )
            {
                System.out.println( "hi" );
            }
            else
            {
                System.out.println( "hello" );
            }
        }

        public static Date showDate(){
            return new Date();

        }

you're first check throws a null pointer exception if the object is actually null. the correct way to check it is with the == comparison. — Liam Clark, Jan 22 '16 at 12:22

score -8 · Answer 4 · edited Jan 22 '16 at 12:06

-8

You can check with an if-else statement, like this:

if (date.equals(null)) {
    //something
} else {
    //something
}

edited Jan 22 '16 at 12:06

N3dst4

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answered Jan 22 '16 at 11:35

Raju

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If your date is null this results in a null pointer exception. – andrzej.szmukala Apr 19 '18 at 13:11

null check with Date object

4 Answers4