What's wrong with this Java code please?

Question

Let:
public class record {
	String name;
	public void show(){
		System.out.println("Name: "+name);
	}
}

This one works very well:
public class test {
	static record rec;
	public static void main(String[] args) {
		rec = new record;
		rec.name="Toky";
		rec.show();
	}
}

So what's wrong with this one ? (no error during the edition, but can't run with the message : Exception in thread "main" java.lang.NullPointerException
	at BPlusTree.test.main(test.java:8))

public class test {
	static record[] rec;

	public static void main(String[] args) {
		rec = new record[2];
		rec[1].name="Toky";
		rec[1].show();
	}
}

THANKS A LOT.

Mister B · Accepted Answer

Just glancing at it I would say that rec[1] should be rec[0], but that does not work either.  The error refers to the array being null.  When rec[0] or rec[1] is null it cannot have a name assigned to its name variable.  This worked for me:

static record recTmp;
static record[] rec;

public static void main(String[] args)
{
recTmp = new record();
rec = new record[2];
        
recTmp.name = "Toky";
rec[0]=recTmp;
rec[0].show();
}

Trending News

What's wrong with this Java code please?

1 Answer