Learn Java DAY2 from scratch

Class Test//class class {public    static void Main (string[] args)    {        System.out.println ("Hello world\n");}    }

Hellow world!!!

A class is equivalent to a class file, and if there are two classes in a Java file, then a two class file will be generated after compilation

class file When Java runs the file, do not want EXE as can double-click execution

Watching

/**

Document comments

*/

Single-line Comment

/* Multiline Comment */

The keywords are all lowercase

Name naming

Class, Interface xxxxyyyyzzzz

Package name Xxxyyyzzz

Variable name xxxyyyzzz

Constant name Xxxyyyzzz

Syntax rules are the same as C + +

Decimal to 16 binary tricks,

int a

Always remove four-bit and 15-phase

Shift right to prevent negative a>>>4

Learn Java DAY2 from scratch