Difference between revisions of "Java"
Jump to navigation
Jump to search
(Created page with "20220531 Fist notes on java progamming. <syntaxhighlight lang=java> public class HelloWorld { public static void main(String args[] ) { String text = "hello world"; Sys...") |
|||
| Line 1: | Line 1: | ||
20220531 | 20220531 | ||
| − | Fist notes on java | + | Fist notes on java programming. |
<syntaxhighlight lang=java> | <syntaxhighlight lang=java> | ||
| Line 15: | Line 15: | ||
=Variables= | =Variables= | ||
;int var1 = 0 | ;int var1 = 0 | ||
| − | :Variables must be declared and | + | :Variables must be declared and initialized |
| + | |||
| + | ;private int var1; | ||
| + | :Private variables in classes can only be accessed from within the class (same for methods). | ||
| + | |||
| + | =Methods= | ||
| + | * Every program must have a main method, that is executed when the program starts | ||
| + | * A 'void' method is a method with no return value, else the return value type must be specified | ||
| + | * Private methods in classes can only be accessed from within the class (same for variables). | ||
Revision as of 11:04, 17 June 2022
20220531
Fist notes on java programming.
public class HelloWorld {
public static void main(String args[] ) {
String text = "hello world";
System.out.println( text );
}
}
If a class implements an interface all methods in that interface must be defined in the class
Variables
- int var1 = 0
- Variables must be declared and initialized
- private int var1;
- Private variables in classes can only be accessed from within the class (same for methods).
Methods
- Every program must have a main method, that is executed when the program starts
- A 'void' method is a method with no return value, else the return value type must be specified
- Private methods in classes can only be accessed from within the class (same for variables).