Java classpath with and without colon ‘:’

I'm learning Java. I have a quirk that I think only experienced people can answer (I've completed the whole list of similar questions on so)

This is valid when compiled in eclipse and run from the command line

java -classpath : test.class

And this is not

java test.class

No directory specified

java -classpath bin test.class

But specified with the colon does

java -classpath bin: test.class

This is my understanding

>By default, Java checks the current working Directory > use colons only if you specify multiple paths

Solution

You want to run "java test" instead of "java test. Class"

Cheers!