javaÖÐ== ÓëequalsµÄÇø±ð
public class test1
{
public static void main(String[] args){
//== ÓëequalsµÄÇø±ð
//1.nullµÄ±È½Ï£ºÖ»ÄÜÓÃ==
System.out.println("1.nullµÄ±È½Ï£ºÖ»ÄÜÓÃ==");
Object o1=null,o2=null;
System.out.println(null==null&&o1==null&&o1==o2);//true
//System.out.println(o1.equals(o2)) //Å׳öÒì³£
//2.»ù±¾ÀàÐ͵ıȽϣºÖ»ÄÜÓÃ==
System.out.println("\n\n2.»ù±¾ÀàÐ͵ıȽϣºÖ»ÄÜÓÃ==");
double i=2.4,j=2.4;
System.out.println(i==j);//true
//3.ÒýÓõıȽϣºµ±×ÓÀàÖØÐ´¹ýequalsÖ®ºó£¬ ==ÓëequalsµÄ±È½ÏЧ¹û²¢²»Í¬£¬e.g String
//==Ï൱ÓÚ×îÔʼµÄequals
/*¸ùÀàObjectÓÐÈçÏ´úÂë
* public boolean equals(Object obj) {
* return (this == obj);
* }
* */
System.out.println("\n\n3.ÒýÓõıȽϣº" +
"µ±×ÓÀàÖØÐ´¹ýequalsÖ®ºó£¬ ==ÓëequalsµÄ±È½ÏЧ¹û²¢²»Í¬£¬e.g String");
String str1=new String("string"),str2=new String("string"),str3=str1;
System.out.println(str3==str1&&str3.equals(str1));//Ö¸Ïòͬһ¶ÔÏó£¬true
System.out.println(str1==str2);//²¢²»Ö¸Ïòͬһ¸ö¶ÔÏó£¬false
System.out.println(str1.equals(str2));//ÓÉÓÚequals±»ÖØÐ´ÁË£¬
//Ö»±È½Ï ËûÃǵÄÖµ£¬ËùÒÔ±¾Àý·µ»Øtrue
//4.×¢ÒâµÄµØ·½,new String() ÓëÖØÔØ·ûºÅ=µÄÇø±ð
System.out.println("\n\n4.×¢ÒâµÄµØ·½,new String() ÓëÖØÔØ·ûºÅ=µÄÇø±ð");
System.out.println("string"=="string");//·µ»Øtrue,˵Ã÷Ö¸ÏòµÄÊÇͬһ¸ö¶ÔÏó
System.out.println(new String("string")=="string");//·µ»Øfalse
}
}
Ïà¹ØÎĵµ£º
·ºÐÍÊÇJava SE 1.5µÄÐÂÌØÐÔ£¬·ºÐ͵ı¾ÖÊÊDzÎÊý»¯ÀàÐÍ£¬Ò²¾ÍÊÇ˵Ëù²Ù×÷µÄÊý¾ÝÀàÐͱ»Ö¸¶¨ÎªÒ»¸ö²ÎÊý¡£ÕâÖÖ²ÎÊýÀàÐÍ¿ÉÒÔÓÃÔÚÀà¡¢½Ó¿ÚºÍ·½·¨µÄ´´½¨ÖУ¬·Ö±ð³ÆÎª·ºÐÍÀà¡¢·ºÐͽӿڡ¢·ºÐÍ·½·¨¡£
¡¡¡¡JavaÓïÑÔÒýÈë·ºÐ͵ĺô¦Êǰ²È«¼òµ¥¡£
¡¡¡¡ÔÚJava SE 1.5֮ǰ£¬Ã»ÓзºÐ͵ÄÇé¿öµÄÏ£¬Í¨¹ý¶ÔÀàÐÍObjectµÄÒýÓÃÀ´ÊµÏÖ²ÎÊýµÄ“È ......
javaдÎļþÂÒÂë
StringBuffer sb = new StringBuffer();
sb.append("<table border=\"0\" width=\"100%\" cellpadding=\"0\" cellspacing=\"1\" bgcolor=\"b5d6e6\"");
sb.append("<tr>");
sb.append("<td bgcolor=\"#FFFFFE\" height=\"42\" colspan=\""+ (jsd ......
Éè¼ÆÄ£Ê½
Ò»¸ö³ÌÐòÔ±¶ÔÉè¼ÆÄ£Ê½µÄÀí½â:
“²»¶®”ΪʲôҪ°ÑºÜ¼òµ¥µÄ¶«Î÷¸ãµÃÄÇô¸´ÔÓ¡£ºóÀ´Ëæ×ÅÈí¼þ¿ª·¢¾ÑéµÄÔö¼Ó²Å¿ªÊ¼Ã÷°×ÎÒËù¿´µ½µÄ“¸´ÔӔǡǡ¾ÍÊÇÉè¼ÆÄ£Ê½µÄ¾«ËèËùÔÚ£¬ÎÒËùÀí½âµÄ“¼òµ¥”¾ÍÊÇÒ»°ÑÔ¿³×¿ªÒ»°ÑËøµÄģʽ£¬Ä¿µÄ½ö½öÊÇ×ÅÑÛÓÚ½â¾öÏÖÔÚµÄÎÊÌ⣬¶øÉè¼ÆÄ£Ê½µÄ“¸´ÔÓ&rdq ......
±¾ÎÄÊ×ÏÈÉè¼ÆÒ»¸öµ¥´Î¶¨Ê±Æ÷Timer+TimerTask£¬È»ºóÔٴλù´¡ÉÏÉè¼ÆÒ»¸öÑ»·¶¨Ê±Æ÷¡£
ÎÒ½«°Ñ java.util.Timer ºÍ java.util.TimerTask ͳ³ÆÎª Java ¼ÆÊ±Æ÷¿ò¼Ü£¬ËüÃÇʹ³ÌÐòÔ±¿ÉÒÔºÜÈÝÒ׵ؼƻ®¼òµ¥µÄÈÎÎñ£¨×¢ÒâÕâЩÀàÒ²¿ÉÓÃÓÚ J2ME ÖУ©¡£²»¹ý£¬Java ¼ÆÊ±Æ÷¿ò¼ÜûÓÐ× ......
JAVA¿ÉÒÔ˵ÊÇ´ÓC++·¢Õ¹ÆðÀ´µÄÍêÈ«ÃæÏò¶ÔÏóµÄ¿ª·¢ÓïÑÔ,Á½ÕßµÄʵÖÊÇø±ðÊÇÀûÒæ·ÖÊô²»Í¬µÄ¹«Ë¾:SUNºÍ΢Èí.¶Ô´Ë΢Èí·¢²¼ÁË.NETÓëÖ®¿¹ºâ.
´Ó×îеÄVisual Studio .NET 2005¿´,.NETÖ÷ÒªÊÇ4ÖÖÓïÑÔ:VB.NET, C#, C++.NET, J#.
VB.NET¿ÉÒÔ˵ÊÇVB6µÄÉý¼¶,µ«ÎÒÈÏΪVB.NETºÍC#ÒѾÊÇÍêȫȫеÄÓïÑÔÁË,Á½ÕßµÄÄ¿µÄ¶¼ÊÇÒª´ò°ÜJAVAÕâ¸ö¾ºÕù¶ ......