java×Ü½á µÚÆßÕÂ
µÚÆßÕÂ
¸ß¼¶ÀàÌØÕ÷
static
ÀàÊôÐÔÓɸÃÀàµÄËùÓÐʵÀý¹²Ïí
public static int total=0;
µ±totalËùÊôÀà±»Êý´ÎʵÀý»¯µÄʱºò totalÖ»ÓÐÒ»¸ö¶ø²»ÊǶà¸ö
Ò²¿É¾²Ì¬³õʼ»¯static
public static int total£»
static{
total=100;
}
static±ê¼ÇµÄ±äÁ¿»òÕß·½·¨ÓÉÕû¸öÀà(ËùÓÐʵÀý)¹²Ïí
µ¥×Óģʽ
class Single{
private static Single onlyone = new Single();
private String name;
public static Single getSingle() {
return onlyone;
}
private Single() {}
}
public class TestSingle{
public static void main(String args[]) {
Single s1 = Single.getSingle();
Single s2 = Single.getSingle();
if (s1==s2){
System.out.println("s1 is equals to s2!");
}
}
static¿ÉÒÔÐÞÊαäÁ¿ ·½·¨ ÄÚ²¿Àà
final¿ÉÒÔÐÞÊÎÀà ÊôÐÔ ·½·¨
final±ê¼ÇµÄÀ಻Äܱ»¼Ì³Ð
final±ê¼ÇµÄ·½·¨²»Äܱ»×ÓÀàÖØд
final±ê¼ÇµÄ±äÁ¿ ³ÉÔ±±äÁ¿»òÕß¾Ö²¿±äÁ¿ ¼´³ÆΪ³£±äÁ¿ Ö»Äܸ³ÖµÒ»´Î
final±ê¼ÇµÄ³ÉÔ±±äÁ¿±ØÐëÔÚÉùÃ÷µÄͬʱºóÔÚÿ¸ö¹¹Ôì·½·¨ÖÐÏÔʽ¸³Öµ ²ÅÄÜʹÓÃ
³éÏóÀà
abstract class
{
void run();
void rub2()
{ }
}
extends ¼Ì³Ð³éÏóÀà ³éÏó·½·¨ÔÚÖ÷º¯ÊýÍâÖØд
abstarctÐÞÊÎÀàʱºò½Ð³éÏóÀà ÐÞÊη½·¨½Ð³éÏó·½·¨
º¬ÓгéÏó·½·¨µÄÀà±ØÐë±»ÉùÃ÷Ϊ³éÏóÀà
³éÏóÀà±ØÐë±»¼Ì³Ð ³éÏó·½·¨±ØÐë±»ÖØд
³éÏóÀ಻Äܱ»ÊµÀý»¯
³éÏó·½·¨Ö»ÐèÒªÉùÃ÷²»ÐèҪʵÏÖ
public interface runnner
{
public void start();
public void run();
}
½Ó¿Ú±»¼Ì³Ðimplements
·½·¨±»ÖØд
class person entends Àà»òÕß³éÏóÀà implements
½Ó¿Ú1£¬½Ó¿Ú2
{
·½
Ïà¹ØÎĵµ£º
ÀàµÄ³õʼ»¯ºÍ¶ÔÏó³õʼ»¯ÊÇ JVM ¹ÜÀíµÄÀàÐÍÉúÃüÖÜÆÚÖзdz£ÖØÒªµÄÁ½¸ö»·½Ú£¬Google ÁËÒ»±éÍøÂ磬ÓйØÀà×°ÔØ»úÖƵÄÎÄÕµ¹ÊDz»ÉÙ£¬È»¶øÀà³õʼ»¯ºÍ¶ÔÏó³õʼ»¯µÄÎÄÕ²¢²»¶à£¬ÌرðÊÇ´Ó×Ö½ÚÂëºÍ JVM ²ã´ÎÀ´·ÖÎöµÄÎÄÕ¸üÊÇÏÊÓÐËù¼û¡£
±¾ÎÄÖ÷Òª¶ÔÀàºÍ¶ÔÏó³õʼ»¯È«¹ý³Ì½øÐзÖÎö£¬Í¨¹ýÒ»¸öʵ¼ÊÎÊÌâÒýÈ룬½«Ô´´úÂëת»»³É JVM ×Ö½ÚÂëºó£¬ ......
Îå¡¢javaµÄÃæÏò¶ÔÏó³ÌÐòÉè¼Æ(ÀàºÍ¶ÔÏó)
/**
* ÃæÏò¶ÔÏóÖ®Ò»
* ÀàÓë¶ÔÏó
*/
/**
* ¶ÔÏóµÄʵÀý»¯¹ý³Ì:
* 1,javaÖÐËùÓÐÀàÐÍÔÚÄÚ´æµÄ·ÖÅäÇé¿ö
* a,»ù±¾ÀàÐÍ"±äÁ¿"char,byte,short,int,long,float,double,boolean´æ´¢ÔÚ¶ÑÕ»ÖÐ
* ¶ÑÕ»ÊÇͨ¹ý¶ÑÕ»Ö¸Õë°´ÕÕÏȽøÏȳöµÄ¶ÁÈ ......
µÚÎåÕ Êý×é
Êý×éʱ¶à¸öÏàͬÀàÐÍÊý¾ÝµÄ×éºÏ
Êý×éÊôÓÚÒýÓÃÀàÐÍ Êý×éÐÍÊý¾ÝΪ¶ÔÏó(object)
ÿ¸öÔªËØÏ൱ÓڸöÔÏóµÄ³ÉÔ±±äÁ¿
Êý×éµÄÔªËØ¿ÉÒÔÊÇÈκÎÊý¾ÝÀàÐÍ °üÀ¨»ù±¾ÀàÐͺÍÒýÓÃÀàÐÍ
int a[];
Mydate a[]; ÒýÓÃÀàÐÍÊý×é
javaÖÐÉùÃ÷Êý×éʱ²»ÄÜÖ¸¶¨Æ䳤¶È int a[5];·Ç·¨
javaÖÐʹÓÃnewÀ´´´½¨Êý×é¶ÔÏó
int a[]=new int[10 ......
µÚÁùÕÂ
javaÀàÉè¼Æ
extendsÀàµÄ¼Ì³Ð
objectÀàÊÇËùÓÐjavaÀàµÄ×î¸ß²ã¸¸Àà
javaÖ»Ö§³Öµ¥¼Ì³Ð ²»ÔÊÐí¶àÖؼ̳Ð
Ò»¸ö×ÓÀàÖ»ÓÐÒ»¸ö¸¸Àà Ò»¸ö¸¸Àà¿ÉÓÃÓжà¸ö×ÓÀà
public default protected public
·½·¨ÖØд
ÔÚ×ÓÀà¿ÉÓøù¾ÝÐèÒª¶Ô¸¸Àà¼Ì³ÐµÄ·½·¨½øÐиÄÔì--·½·¨µÄÖØд
ÖØд·½·¨±ØÐëºÍ±»ÖØд·½·¨¾ßÓÐÏàͬµÄ·½·¨Ãû³Æ ²ÎÊýÁбí ......