why is it mandatory to pass string arg[] as an argument in main method? why we cannot pass any other data type available in java? whats the importance of passing String arg[] in main method in java?
History. This is a convention since the days of C, maybe even earlier? Java took most of its syntax from C.
Also, command line arguments are Strings which is why that is the data type. Collections did not exist in Java 1 so they were not an option. Arrays did exist.