"Java" java_03 the first Java program

the first JAVA program is written and run

1. Edit with Notepad

 Public class welcome{    publicstaticvoid  main (string[] agrs) {        System.out.println ("Hello world!" );    }}

2. Save As: D://mycode/welcome.java

3. Go to the console and enter: d://mycode/directory.

4.javac Welcome.java

5.java Welcome

6. The result of the operation:

analysis of running mechanism of Java program

high-level programming language types for computers : compiled, interpreted. The Java language is a combination of two types;

First step: Compiling

Use the compiler (Javac) to compile the source program into bytecode-byte-code file name: source file name. class

Part II: Running

Use the virtual machine (interpreter,Java) to interpret the Execute class bytecode file.

"Java" java_03 the first Java program