Enumtest:
Enumeration types are reference types, but small, MEDIUM, and large are not referenced by an object. An enumeration is not part of the original data type, and each of its specific values refers to a specific object, and the same value refers to the same object.
string addition:
The previous "X+y" +x+y the default is to first add one character at home one character, the latter x+y+ "X+y" is to add the number before adding characters.
Binary representation of numeric values:
The original code: is the binary fixed-point notation, that is, the highest bit is the sign bit, "0" is positive, "1" is negative, the remaining bits represent the size of the value.
Inverse code:: The inverse code of positive number is the same as its original code; the inverse code of negative number is the inverse of its original code, except the sign bit.
Complement: The complement of a positive number is the same as its original code; the complement of a negative number is the minus 1 of its inverse code.
Java positive number is the original code, negative numbers with the inverse code.
Scope of the variable:
The output should be a value of the nearest value from System.out.print (value), and it will be written in public static void main (string[] args) {}.
Java hands-on brain