public class {
public static void main (String args[])
{
, ;
}
, ++
}
2. :
{ }
- main
Java - , .
public class Prog{
public static void main (String args[])
{
System.out.println("Hello Java!");
}
}
Prog. public, , , . class, . , .
Java main, Prog. . . :
public static void main (String args[])
Java main , .
public, , . static , main - , void - . - String args[] - args, String, . .
, .
Java : // . /* */.
/** */, :
@ author ;
@ version
@exception ;
@param , ;
@return - , ;
, .
/** @return */
, .
int x; // x = 10; // System.out.println(x); // 10 |
. :
1 2 | int x = 10; // System.out.println(x); // 10 |
, , , :
|
|
int x;
System.out.println(x);//
:
int x, y;
x = 10;
y = 25;
System.out.println(x); // 10
System.out.println(y); // 25
:
int x = 8, y = 15;
System.out.println(x); // 8
System.out.println(y); // 15
, :
int x = 10;
System.out.println(x); // 10
x = 25;
System.out.println(x); // 25
Var -
Java 10 var, :
var x = 10;
System.out.println(x); // 10
var , , .
var, , , , , , :
var x; //! ,
x = 10;
, Java . . , , final:
final int LIMIT = 5;
System.out.println(LIMIT); // 5
// LIMIT=57; // , LIMIT -
, .
Java , . , . , .
, , Java. .
boolean | 1 | false, true | false |
byte | 1 | -128.. 127 | 0 |
char | 2 | 0.. 65 535 | 0 |
short | 2 | -32768.. 32767 | 0 |
int | 4 | -231..231-1 | 0 |
float | 4 | 3.40282347E+38 | 0.0 |
double | 8 | 1.797693134486231570E+308 | 0.0 |
. , . , .
int x=154, y=-154; // 10 int
int num111 = 0x6F; // 16- , 111
int num8 = 010; // 8- , 8
int num13 = 0b1101; // 2- , 13
:
int x = 123_456;
int y = 234_567__789;
System.out.println(x); // 123456
System.out.println(y); // 234567789