در مورد Java.IO

1. 1. The data transfer occurs in the format of streams in java. we can transfer the data in and out.
   2. The constructor of System class is defined as private; we can not create object of system class. In System class there are 3 static variables 1-in 2-out 3-error   
   • in: is the object of InputStream class.
   • out: is the object of PrintStream class.
   • err: is the object of PrintStream class.