Java-basic-1

1.

Java Standard Edition (Java SE)

Java Enterprise Edition (Java EE):

Geared toward developing large-scale, distributed networking applications and web-based Applications
Java Micro Edition (Java ME):
Geared toward developing applications for small, memory-constrained devices, such as cell phones, pagers and PDAs.

2. Javadoc Comments:

Start with/**, */end; Javadoc Utility program read Javadoc to do HTML documents

3. Implicitly imports Java.lang, so do not write

4.

Class naming: The first letter of each word capitalized: ClassName, cannot start with a number

Naming of variables and functions: First letter lowercase, other initial capitals: Variname

5.

Turn into. class containing Java bytecodes
Javac Filename.java
Javac *.java multiple Java files compile at the same time
Translated by the JVM for OS, execute
Java fileName

6. Integer Division: The fractional part is discarded directly

7. Static method:
You do not need to create an instance of it to work with. Main is static and can have a main in each class, depending on which Java command to use.

8.

Primitive types:
Boolean, Byte, char, short, int, long, float, double
Reference types:
Objects that is referenced may each contain many instance variables and methods. Not primitive, or reference.

Here is the code time:)

For dialog windowimport javax.swing.joptionpane;//only one Publicpublic class Test {public static void main (string[] Ar GS) {//Standard output object. To command LineSystem.out.print ("first");//Add/nsystem.out.println ("Hello world!"); /Format-controlfloat i = 3.2f; System.out.printf ("%s\n%.2f", "Hello", I);//Input dialog window. Get input. String name = Joptionpane.showinputdialog ("What ' s your name?"); /format control of stringstring msg = String.Format ("Welcome,%s", name);//first:position of window. NULL = Centerjoptionpane.showmessagedialog (null, MSG);}}

　　

Java-basic-1