is class name important ?

Hi all,

I have two simple classes

1. 123_test.java

class 123_test

{

}

2. test_123.java

class test_123

{

}

I can compile second one successfully. But when I compile first one , the error is

123_test.java:1: <identifier> expected

class 123_test

^

1 error

is problem class name starting with a number ?

Thanks,

[587 byte] By [Terry_ba] at [2007-11-27 9:54:43]