arrays are static, fixed length you have to declare the length first. Therefore you can easily get the .length of an array (primitive). Where as of strings you need to count the char with in the string class(think blob) to get the count or length() (method) of a string.

don't confuse the ArrayList() with standard Array[]; they are similar but ArrayList() is a class and Array[] is more primitive.

hope this helps.

try going in to the path where your dist directory within your program.
D:java\Pratic\d ist\
then java -jar <name>.jar