Section 10.2 of Java conventions recommends using class names instead of objects to use static variables or methods, i.e.
MyClass.methodName1() instead of
MyClass Obj1 = new MyClass(); Obj1.variable1; Obj1.methodName1();
There is no explanation of the rationale behind this, although I suspect this has something to do with memory use. It would be great if someone could explain this.
I guess you mean "for static methods and variables".
There is no difference regarding memory, except of course if you create the instance just for calling the method. Conventions aren't for memory efficiency but for coder efficiency, which is directly related with the readability of the code.
The rationale is that by reading
you know it's a static method and that it can't use or change your
And if you write
obj1.variable1; // note the "o" instead of "O", please do follow conventions
then the reader has to read your source code to know if variable1 is static or not.