Question

class TestMe{   
    public static void main (String args[]){
        String s3;  
        System.out.print(s3);
    }
}

why the compiler is giving a error,refernce object has a default value of null,why it is not the output…??

error: variable s3 might not have been initialized

Answer 1

local variables should be initialized before using them, local vars dont get default values in java, thus your string s3 doesn’t get default value null as it is a local variable , thus the compiler error.

Fom JLS:

If a declarator does not have an initialization expression, then every
reference to the variable must be preceded by execution of an
assignment to the variable, or a compile-time error occurs by the
rules of §16.