"Getting Started with Java" Hello World

1, the development of Java Program 3 steps: Edit, compile, run.

Edit: stored as text, suffix. java;

Compile: Generate an executable. class file;

Javac  Programname.java

Run: Terminal window input

Java  programname

2. Error message: Compile error, run-time error, logic error.

3. Command line Parameters

The program can accept command-line arguments, the first command-line argument is args[0], the second is args[1], ...

Java and C language, counting starting from 0;

In C language, the number of command line arguments argc, command line parameters argv;

The function prototype is

int Main (intchar *argv);

4. For loop in Java is different from C language

The C language needs to define variables (if needed) at the beginning of the code block that the curly braces mark, and the Java language is not limited by this.

 for (int i = 0; i < num; i++) // Java

5, System.out.print () and System.out.println () difference: the latter after printing the line.

"Getting Started with Java" Hello World