Question

I want to know about the symbol % that is written while setting the classpath or while setting the path for the jdk in command prompt in windows.
E.X.

set classpath=%classpath% ;.;

or

set path=%path% ;.;C:\Program Files\Java\jdk1.7.0_01

I want to know about %path% and %classpath%

What do they mean and what is the special % symbol about?

Answer 1

The % notation is used to access environment variables in windows. E.g. in the line

set classpath=%classpath%;.

the part %classpath% is replaced with the current content of this variable and then appended by ;. and then rewritten to the same variable.

On command line promt you can write e.g.

echo %classpath%

which will show you the content directly (as with set classpath).