java×Ö·û´®´¦Àíº¯ÊýÁбíÒ»ÀÀ
javaÖеÄ×Ö·û´®Ò²ÊÇÒ»Á¬´®µÄ×Ö·û¡£µ«ÊÇÓëÐí¶àÆäËûµÄ¼ÆËã»úÓïÑÔ½«×Ö·û´®×÷Ϊ×Ö·ûÊý×é´¦Àí²»Í¬£¬Java½«×Ö·û´®×÷ΪStringÀàÐͶÔÏóÀ´´¦Àí¡£½«×Ö·û´®×÷ΪÄÚÖõĶÔÏó´¦ÀíÔÊÐíJavaÌṩʮ·Ö·á¸»µÄ¹¦ÄÜÌØÐÔÒÔ·½±ã´¦Àí×Ö·û´®¡£ÏÂÃæÊÇһЩʹÓÃÆµÂʱȽϸߵĺ¯Êý¼°ÆäÏà¹ØËµÃ÷¡£
substring()
ËüÓÐÁ½ÖÖÐÎʽ£¬µÚÒ»ÖÖÊÇ£ºString substring(int startIndex)
µÚ¶þÖÖÊÇ£ºString substring(int startIndex,int endIndex)
concat() Á¬½ÓÁ½¸ö×Ö·û´®
replace() Ìæ»»
ËüÓÐÁ½ÖÖÐÎʽ£¬µÚÒ»ÖÖÐÎʽÓÃÒ»¸ö×Ö·ûÔÚµ÷ÓÃ×Ö·û´®ÖÐËùÓгöÏÖij¸ö×Ö·ûµÄµØ·½½øÐÐÌæ»»£¬ÐÎʽÈçÏ£º
String replace(char original,char replacement)
ÀýÈ磺String s=”Hello”.replace(’l',’w');
µÚ¶þÖÖÐÎʽÊÇÓÃÒ»¸ö×Ö·ûÐòÁÐÌæ»»ÁíÒ»¸ö×Ö·ûÐòÁУ¬ÐÎʽÈçÏ£º
String replace(CharSequence original,CharSequence replacement)
trim() È¥µôÆðʼºÍ½áβµÄ¿Õ¸ñ
valueOf() ת»»Îª×Ö·û´®
toLowerCase() ת»»ÎªÐ¡Ð´
toUpperCase() ת»»Îª´óд
length() È¡µÃ×Ö·û´®µÄ³¤¶È
Àý£º
char chars[]={’a',’b’.’c'};
String s=new String(chars);
int len=s.length();
charAt() ½ØÈ¡Ò»¸ö×Ö·û
Àý£º
char ch;
ch=”abc”.charAt(1);
·µ»ØÖµÎª’b’
getChars() ½ØÈ¡¶à¸ö×Ö·û
void getChars(int sourceStart,int sourceEnd,char target[],int targetStart)
sourceStart Ö¸¶¨ÁË×Ó´®¿ªÊ¼×Ö·ûµÄϱê
sourceEnd Ö¸¶¨ÁË×Ó´®½áÊøºóµÄÏÂÒ»¸ö×Ö·ûµÄϱꡣÒò´Ë£¬×Ó´®°üº¬´ÓsourceStartµ½sourceEnd-1µÄ×Ö·û¡£
target Ö¸¶¨½ÓÊÕ×Ö·ûµÄÊý×é
targetStart targetÖпªÊ¼¸´ÖÆ×Ó´®µÄϱêÖµ
Àý£º
String s=”this is a demo of the getChars method.”;
char buf[]=new char[20];
s.getChars(10,14,buf,0);
getBytes()
Ìæ´úgetChars()µÄÒ»ÖÖ·½·¨Êǽ«×Ö·û´æ´¢ÔÚ×Ö½ÚÊý×éÖУ¬¸Ã·½·¨¼´getBytes()
Àý£º
String s = “Hello!ÄãºÃ£¡”;
byte[] bytes = s.getBytes();
toCharArray()
Àý£º
String s = “Hello!Äã
Ïà¹ØÎĵµ£º
ÀàµÄ³õʼ»¯ºÍ¶ÔÏó³õʼ»¯ÊÇ JVM ¹ÜÀíµÄÀàÐÍÉúÃüÖÜÆÚÖзdz£ÖØÒªµÄÁ½¸ö»·½Ú£¬Google ÁËÒ»±éÍøÂ磬ÓйØÀà×°ÔØ»úÖÆµÄÎÄÕµ¹ÊDz»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£¬ ......
ÎÊ£º
²âÊÔÐÂÊÖ£¬¸ù¾Ý×Ô¼ºÀí½âдµÄµ¥Ôª²âÊÔÓÃÀýÄ£°å£¬µ«ÊÇ¿ª·¢ÈËÔ±(JAVAÓïÑÔ)·´Ó³ÄÑÒÔʵʩ£¬²»ÖªµÀµ½µ×Ó¦¸ÃÈçºÎ¸ÄÕý£¬ÎÒÔ±¾µÄÏë·¨ÊÇÒÔÀàΪµ¥Î»£¬ÎªÈ·±£²âÊÔ¸²¸ÇÂÊ£¬ÏÈ»¿ØÖÆÁ÷ͼ£¬ÒÀ¾Ý¶ÀÁ¢Â·¾¶È·¶¨ÊäÈëÊä³ö£¬ÓÐÁËÊäÈëÊä³ö¾ÍËãÒ»¸öÓÃÀýÁË£¬µ«´ó¼Ò·´Ó³£¬Ò»ÀàΪµ¥Î»»¿ØÖÆÁ÷ͼ²»ºÃ»£¬ÀàÖпÉÄÜÉæ¼°ºÜ¶àº¯Ê ......
Ò»¡¢Í¬²½ÎÊÌâÌá³ö
Ï̵߳Äͬ²½ÊÇΪÁË·ÀÖ¹¶à¸öÏ̷߳ÃÎÊÒ»¸öÊý¾Ý¶ÔÏóʱ£¬¶ÔÊý¾ÝÔì³ÉµÄÆÆ»µ¡£
ÀýÈ磺Á½¸öÏß³ÌThreadA¡¢ThreadB¶¼²Ù×÷ͬһ¸ö¶ÔÏóFoo¶ÔÏ󣬲¢ÐÞ¸ÄFoo¶ÔÏóÉϵÄÊý¾Ý¡£
public class Foo {
private int x = 100;
public int getX() {
&nbs ......
Map map = new HashMap();
Iterator it = map.entrySet().iterator();
while (it.hasNext()) {
Map.Entry entry = (Map.Entry) it.next();
Object key = entry.getKey();
Object value = entry.getValue();
}
......
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
public class ConvertMapToList {
/**
* ʵÏÖ½«HashMapת»»³ÉΪArrayList£¬²¢½«mapµÄKey ¡¢Value·Ö± ......