Differences between using public Class and Class to declare classes

In Java, there are two methods to declare a class: public class name and class name.

(1) when using public class to declare a class, the class name must be consistent with the file name; otherwise, the program cannot be compiled.

(2) When using class to declare a class, the class name can be different from the file name, but the generated class * must be executed during execution *. Class file.

(3) A Java file can contain definitions of multiple class classes, but only one public class can be defined.

(4) when defining a class name, the first letter of the class name must be capitalized. This is a naming rule.

Keywords in Java:

(1) Although Goto and const do not have any meaning in Java, they are also reserved words. Like other keywords, they cannot be used as custom identifiers in programs.

(2) True, false, and null are not keywords, but they are used as an identification type and cannot be used directly.

(3) The Assert and enum keywords are newly added in Java. The assert is added in jdk1.4 and The enum is added after jdk1.5.

Differences between using public Class and Class to declare classes