Ò׽ؽØÍ¼Èí¼þ¡¢µ¥Îļþ¡¢Ãâ°²×°¡¢´¿ÂÌÉ«¡¢½ö160KB

ÔÚJavaÖÐÁ½ÖÖ²»Í¬µÄ¶Ô±äÁ¿¸³Öµ·½Ê½

ÔÚJavaÖÐÓÐÁ½ÖÖ²»Í¬µÄ¶Ô±äÁ¿¸³Öµ·½Ê½£¬Ò»ÖÖÊÇÖ±½Ó½«Ò»¸öÖµ¸³¸ø±äÁ¿¡£ÀýÈ磺
int a = 1;
String s = "abc";
Integer in = 125;
ÁíÍâÒ»ÖÖÊÇ´´½¨Ò»¸ö¶ÔÏ󣬲¢½«Æä¸³¸øÒ»¸ö±äÁ¿¡£ÀýÈ磺
String s = new String("abc")
Integer in = new Integer(125);
Á½ÖÖ·½Ê½µÄ²»Í¬Ö®´¦ÔÚÓÚ£º
µÚÒ»ÖÖ·½Ê½±äÁ¿µÄÖµ´æ´¢ÔÚ¶ÑÕ»ÖУ¬µ±ÏÂÒ»´Î¶¨ÒåÒ»¸öеıäÁ¿£¬Èç¹ûÓëÇ°ÃæµÄij¸ö±äÁ¿ÀàÐÍÏàͬ£¬²¢ÇÒÖµÏàͬµÄÇé¿öÏ£¬²»»á²úÉúеÄÖµ£¬¶ø½ö½ö²úÉúÒ»¸öеÄÒýÓᣱÈÈ磺
int a1 = 1;
int a2 = 1;
String s1 = "abc";
String s2 = "abc";
ÉÏÃæµÄ´úÂëÖУ¬a1 Óë a2 ÊǶÔͬһ¸ö±äÁ¿ÖµµÄÒýÓá£s1 Óë s2 Ò²ÊǶÔͬһ¸ö±äÁ¿ÒýÓá£ÕâÒ²ÊÇΪʲôͨ¹ý"=="ÅжÏËûÃÇÖ®¼äµÄ¹ØÏµÊ±£¬»á·µ»ØtrueµÄÔ­Òò¡£
µÚ¶þÖÖÇé¿öÏ£¬Ã¿´Îµ÷ÓÃnewµÄʱºò£¬java»á²úÉúÒ»¸öеĶÔÏ󣬲¢´æ·ÅÔÚ¶ÑÖС£²»¹ÜÇ°ÃæÊÇ·ñ´æÔÚÄÚÈÝÏàͬµÄ¶ÔÏó¡£java¶¼»á²úÉúÒ»¸öеĶÔÏó¡£ÀýÈç¡£
String s1 = new String("abc");
String s2 = new String("abc");
ÔÚÉÏÃæµÄ´úÂëÖУ¬s1ºÍs2Ö¸ÏòµÄÊDz»Í¬µÄ¶ÔÏó£¬ÕâÒ²ÊÇΪʲôʹÓÃ"=="ÅжÏËûÃÇʱºò·µ»ØfalseµÄÔ­Òò¡£
ÐèҪעÒâµÄÊÇ£¬ÕâÀï´æÔÚÒ»¸öÌØÊâÇé¿ö£¬Ò²¾ÍÊǵ±ÊÊÓ¦jdk5µÄ×Ô¶¯²ðÏä»úÖÆµÄʱºò£¬ÀýÈç
int x1 = new Integer(1);
int x2 = new Integer(1);
Õâʱºò£¬ÒòΪ±äÁ¿µÄÀàÐÍÊÇ»ù±¾ÀàÐÍ£¬Javaʵ¼ÊÖ´ÐеÄÊÇ£º
int x1 = 1;
int x2 = 1;
Ò²¾ÍÊÇ˵²¢Ã»ÓзֱðΪx1,x2´´½¨¶ÔÏó£¬x1 ºÍ x2 Ö¸ÏòµÄÊÇͬһ¸ö±äÁ¿¡£
ºóÀ´·¢ÉúÁËһЩС²åÇú£¬ ÊÇÕâÑùµÄ£¬ÎÒµ÷ÊÔÁËÒ»ÏÂÕâ¶Î´úÂ룺
public class Test {
 
  public static void main(String[]args){
          Integer a = 128;
          Integer b = 128;
          String aa = "abc";
          String bb = "abc";
          String aaa = new String("abc");
          String bbb = new String("abc");
          System.out.println(a==b);
          System.out.println(aa==bb);
     &nb


Ïà¹ØÎĵµ£º

finalÔÚjavaÖеÄÓ¦ÓÃ

finalÔÚJavaÖв¢²»³£Óã¬È»¶øËüȴΪÎÒÃÇÌṩÁËÖîÈçÔÚCÓïÑÔÖж¨Òå³£Á¿µÄ¹¦ÄÜ£¬²»½öÈç´Ë£¬final»¹¿ÉÒÔÈÃÄã¿ØÖÆÄãµÄ³ÉÔ±¡¢·½·¨»òÕßÊÇÒ»¸öÀàÊÇ·ñ¿É±»¸²Ð´»ò¼Ì³ÐµÈ¹¦ÄÜ£¬ÕâÐ©ÌØµãʹfinalÔÚJavaÖÐÓµÓÐÁËÒ»¸ö²»¿É»òȱµÄµØÎ»£¬Ò²ÊÇѧϰJavaʱ±ØÐëÒªÖªµÀºÍÕÆÎյĹؼü×ÖÖ®Ò»¡£
final³ÉÔ±
¡¡¡¡ µ±ÄãÔÚÀàÖж¨Òå±äÁ¿Ê±£¬ÔÚÆäÇ°Ãæ¼ÓÉÏfi ......

JAVAÖ®IOÁ÷(³¬ÏêϸµÄJava.io°üµÄ½éÉÜ!)

JAVAÖ®IOÁ÷(³¬ÏêϸµÄJava.io°üµÄ½éÉÜ!)
Ò».InputºÍOutput
1.stream´ú±íµÄÊÇÈκÎÓÐÄÜÁ¦²ú³öÊý¾ÝµÄÊý¾ÝÔ´£¬»òÊÇÈκÎÓÐÄÜÁ¦½ÓÊÕÊý¾ÝµÄ½ÓÊÕÔ´¡£
ÔÚJavaµÄIOÖУ¬ËùÓеÄstream£¨°üÀ¨InputºÍOut stream£©¶¼°üÀ¨Á½ÖÖÀàÐÍ£º
1.1 ÒÔ×Ö½ÚΪµ¼ÏòµÄstream
ÒÔ×Ö½ÚΪµ¼ÏòµÄstream£¬±íʾÒÔ×Ö½ÚΪµ¥Î»´ÓstreamÖжÁÈ¡»òÍùstreamÖÐдÈëÐÅÏ ......

Java»ñÈ¡¸÷ÖÖ³£ÓÃʱ¼ä·½·¨

package com.test;


import java.text.DateFormat;
import java.text.ParsePosition;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;

public class TimeTest {
//ÓÃÀ´ ......

ÓÃJavaʵÏÖ½ñÌì¡¢×òÌ졢ǰÌìµÄÈÕÆÚСÀý×Ó¡£


ÏÂÃæÊÇÓÃJavaʵÏÖ½ñÌì¡¢×òÌ졢ǰÌìµÄÈÕÆÚСÀý×Ó,´ó¼Ò¿ÉÒÔÊÔÊÔ£¬ÓÐʲôÎÊÌâÎÒÃÇ»¥ÏàÌÖÂÛ¡£
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
public class TestStr {
public static void main(String[] args) {
   getDates();
}
public static void getDates() ......

java Îļþ¶ÁÈ¡_InputStreamReader

package test;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
public class Test {
 public static void main(String arg[]) {
  String fileName ......
© 2009 ej38.com All Rights Reserved. ¹ØÓÚE½¡ÍøÁªÏµÎÒÃÇ | Õ¾µãµØÍ¼ | ¸ÓICP±¸09004571ºÅ