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

Java»ù±¾Êý¾ÝÀàÐÍ

 ±äÁ¿,³£Á¿µÄ¸ÅÄî

  JavaÓïÑÔÖÐÓÐÎåÖÖ²»Í¬ÀàÐ͵ij£Á¿,

 
•1ÕûÐͳ£Á¿:ÈκÎÒ»¸öÕûÐÍÊý×Ö¾ÍÊÇÒ»¸öÕûÐͳ£Á¿.
–JavaÓïÑÔÖÐ,ÕûÐͳ£Á¿ÓÐÈýÖÖ±íʾ·½Ê½:
•Ê®½øÖÆ:0,1,2,3,4,5,6,7,8,9,10,11,12…¶¼ÊÇÊ®½øÖƵij£Á¿
•°Ë½øÖÆ:°Ë½øÖÆ¿ÍÁ÷Á¿Ö»ÄÜÓÃ0,1,2,3,4,5,6,7À´±íʾ,ÇÒÖ»ÄÜÓÃ0×÷ΪÊ×λ,ÀýÈç012,02,06¶¼Êǰ˽øÖÆÕûÐͳ£Á¿.

 
 
–2.¸¡µãÐͳ£Á¿
•СÊý¾ÍÊǸ¡µãÐͳ£Á¿,Èç2.53,  9.13455µÈСÊý.
–3. ²¼¶ûÐͳ£Á¿
•²¼¶ûÐͳ£Á¿±íʾÂß¼­Öµ,²»ÊÇÕæ¾ÍÊǼÙ, Ö»ÓÐÁ½¸öÖµ: true »ò false
–4. ×Ö·ûÐͳ£Á¿
•µ¥¸ö×Öĸ»ò·ûºÅ,±ØÐë°üº¬ÔÚµ¥ÒýºÅÄÚ’’,Èç’a’, ‘@’…
–5. ×Ö·û´®³£Á¿
•Javaͨ¹ýË«ÒýºÅ°ÑÒ»Á¬´®µÄ×Ö·ûÀ¨ÆðÀ´µÄÐÎʽ±íʾ×Ö·û´®³£Á¿.Èç”HelloWorld”, “Hello DangDang”
 
 
±äÁ¿
 
³ÌÐòÔÚÔËÐеÄʱºò,ϵͳ»áΪ³ÌÐò·ÖÅäÄÚ´æµ¥ÔªÀ´´æ´¢¸÷ÖÖ³£Á¿Êý¾Ý,±äÁ¿ÊÇÒ»¸ö»ù±¾µÄ´æ´¢µ¥Ôª,±äÁ¿¿ÉÒÔ¿´×÷ÊÇÒ»¸öÈÝÆ÷,ËüÊÇÓÃÀ´×°Ôس£Á¿Êý¾ÝµÄ,¼Çס±äÁ¿¿ÉÒÔ×°ÁËÕâ¸ö³£Á¿,ÔÙ×°ÄǸö³£Á¿,ËùÒÔ±äÁ¿Àï×°µÄ
¶«Î÷ÊÇ¿ÉÒÔ±äµÄ¡£
 
–¸ù¾Ý³£Á¿Êý¾ÝµÄÀàÐÍ,±äÁ¿·ÖΪËĸö´óÀàÐÍ
•ÕûÐÍ:°üÀ¨¶ÌÕûÐÍ,ÕûÐÍ,³¤ÕûÐÍ,×Ö½ÚÐÍ.
•¸¡µãÐÍ:°üÀ¨µ¥¾«¶È¸¡µãÐÍ,Ë«¾«¶È¸¡µãÐÍ.
•²¼¶ûÐÍ:Ö»°üÀ¨²¼¶ûÐÍ.ÓÐÁ½ÖÖÖµ”Õæ/¼Ù”
•×Ö·ûÐÍ:Ö»°üÀ¨µ¥¸ö×Ö·û,´ú±íÊý×Ö,×Öĸ,·ûºÅ…
ÕûÐͱäÁ¿

 
ÕûÐÍÀàÐÍ
´æ´¢ÐèÇó
ÖµµÄ·¶Î§
byte(×Ö½ÚÐÍ)
1 ×Ö½Ú
-128 ~~ 127
short(¶ÌÕûÐÍ)
2 ×Ö½Ú
-32768 ~~ 32767
int(ÕûÐÍ)
4×Ö½Ú
-2147483648 ~~ 2147483647
long(³¤ÕûÐÍ)
8 ×Ö½Ú
-9223372036854775808 ~~ 9223372036854775807
 
¸¡µãÐÍ:µ¥¾«¶È¸¡µãÐÍ(float),Ë«¾«¶È¸¡µãÐÍ(double)
 
ÀàÐÍ
´æ´¢ÐèÇó
±£ÁôСÊýλ
float
4×Ö½Ú
6-7λ
double
8×Ö½Ú
15λСÊý
 
×Ö·ûÐÍ(char)¿É±íʾͨ³£ÒâÒåÉϵĵ¥¸ö×Ö·û,Java×Ö·û²ÉÓÃUnicode±àÂë.UnicodeÊÇÒ»ÖÖ×Ö·û±àÂ뷽ʽ,¿ÉÒÔ¿çÓïÑÔ,¿çƽ̨½øÐÐÎı¾×ª»». Unicode±àÂë,Ò»¸ö×Ö·ûÕ¼Á½¸ö×Ö½Ú.
 
•boolean ÀàÐÍÓÐÁ½¸öÖµ:falseºÍtrue,ÓÃÀ´ÅжÏÂß¼­Ìõ¼þµÄ.
ÕûÐÍÓÃÓÚ±íʾûÓÐСÊý²¿·ÖµÄÊýÖµ,ËüÔÊÐíÊǸºÊý.JavaÌṩÁË4ÖÖÕûÐÍ
 
±äÁ¿


Ïà¹ØÎĵµ£º

Java·ÀÖ¹SQL×¢Èë

 SQL×¢ÈëÊÇ×î³£¼ûµÄ¹¥»÷·½Ê½Ö®Ò»,Ëü²»ÊÇÀûÓòÙ×÷ϵͳ»òÆäËüϵͳµÄ©¶´À´ÊµÏÖ¹¥»÷µÄ,¶øÊdzÌÐòÔ±ÒòΪûÓÐ×öºÃÅжÏ,±»²»·¨
Óû§×êÁËSQLµÄ¿Õ×Ó,ÏÂÃæÎÒÃÇÏÈÀ´¿´ÏÂʲôÊÇSQL×¢Èë:
          ±ÈÈçÔÚÒ»¸öµÇ½½çÃæ,ÒªÇóÓû§ÊäÈëÓû§ÃûºÍÃÜÂë:
     & ......

Java³£ÓÃÅÅÐòËã·¨


package com.xiaobian;   
  
public class BubbleSort {   
    //ðÅÝÅÅÐò   
    public static void bubbleSort(int[] data){   
      &n ......

Java¶þ·Ö·¨

Ìù¶Î´úÂë,ÓÐÉÙÐí×¢ÊÍ:
package ibees;
import java.util.Arrays;
public class BinarySearch {

/**
* @param args
*/
public static void main(String[] args) {
double[] src = new double[]{1.3,9.9,10.89,12.89,89.0};
System.out.println(new BinarySearch().binarySearch(src, 89.0));
}

......

javaÉè¼ÆÄ£Ê½Ðò

³ÌÐòÉè¼ÆÊǽâ¾öÎÊÌâ˼·µÄ¾ßÌ廯.¾ÍÏñ½¨ÔìÒ»×ù·¿×ÓÒ»Ñù£¬ÓÃʲôÑùµÄ²ÄÁÏ,½¨Ôìʲô·ç¸ñµÄ½¨Öþ,¾ßÌåÿ¸öλÖÃÊÇʲô... ²»Í¬µÄ½¨Öþʦ»áÓв»Í¬µÄ·½·¨. ¶ø°ÑÍê³ÉÄ³Ò»ÌØ¶¨ÎÊÌâµÄ½â¾ö˼·¹æ·¶Ò»Ï ¾Í¿ÉÒÔ³Æ×÷ΪһÖÖÉè¼ÆÄ£Ê½.
³ÌÐòÉè¼ÆÖÐÉè¼ÆÄ£Ê½ÎªÎÒÃÇÔÚijһÎÊÌâÓòÌṩÁËÒ»ÖÖÁ¼ºÃµÄʵÏÖ·½·¨²Î¿¼£¬¿ÉÒÔ´ó´óʵÏÖ¸´Óú͸ßЧ¡£
ÏÂÃæÎ ......

javaÐÔÄÜ¼à¿Ø¹¤¾ß btrace

btraceÊÇsunÍÆ³öµÄÒ»¿îjavaÐÔÄÜ¼à¿Ø¹¤¾ß£¬ÀûÓÃjava agent ºÍ jvm attach¼¼Êõ£¬¿ÉÒÔ²»Í£»úµÄÇé¿öÏÂ¼à¿ØÏßÉÏÇé¿ö£¬²¢ÇÒ×öµ½×îÉÙµÄÇÖÈ룬ռÓÃ×îÉÙµÄϵͳ×ÊÔ´¡£
Ïêϸ¼û¹Ù·½Îĵµ
ÁíÍâbtraceÓкÜÑϸñµÄÏÞÖÆ£¬±ÈÈçÆ´½Ó×Ö·û´®¡¢Ñ­»·¡¢µÝ¹é¡¢ÒÔ¼°ÎÒÃÇÆ½Ê±¾­³£ÓõÄһЩ·½·¨¶¼²»¿ÉÒÔÓã¬ËûÓÐËû×Ô¼º×¨ÃŵÄÀà¿â¡£
btrace»¹ÌṩÁËVi ......
© 2009 ej38.com All Rights Reserved. ¹ØÓÚE½¡ÍøÁªÏµÎÒÃÇ | Õ¾µãµØÍ¼ | ¸ÓICP±¸09004571ºÅ