NullPointers in Java

[nandkishor rao]

Does a string variable throws NullPointerException if we try to access
if not then why? Is it because it implements toString()?

[Krishna Rao]

Hi Nandakishore,
String throws Nullpointerexception for sure if it is null.

String s = null;
System.out.println(s.toString());
Gives: Exception in thread "main" java.lang.NullPointerException

Hope this helps

[Peter Chase]

The String class has nothing to do with it.

The variable holds a reference to an object. If the reference is null and you try to call a method using it, you get a NullPointerException. That is true always, regardless of the class of object to which the variable is declared to refer.

Unlike other languages (e.g. C++), Java cannot have variables that hold an object. They always hold a reference to an object, or they hold a primitive like an "int".