]]>
String b="a";
boolean c=(a==b);
涓轟粈涔坈鏄痜alse錛?/p>
String 綾諱笉鏄噰鐢ㄥ叡浜璁℃ā寮忓悧銆傚悓鏍風(fēng)殑瀛楃涓插簲璇ュ紩鐢ㄧ殑鏄悓鏍風(fēng)殑鍦板潃銆傚彲涓轟粈涔堟槸false鍛紵
濡傛灉鏄?br />
String a="a";
String b="a";
boolean c=(a==b);
榪欎釜鏃跺檅灝辨槸true浜?
java.lang.String綾誨澶у鏉ヨ鏈鐔熸?zhèn)変笉杩囦簡(jiǎn)锛屾垜浠啓java紼嬪簭寰堝皯鑳戒笉鐢⊿tring鐨勩傛湰鏂囪榪板浣曟紜殑浣跨敤String錛屽唴瀹逛富瑕佹秹鍙?qiáng)鍒濆鍖栥佷覆鑱斿拰姣旇緝絳夋搷浣溿?
棣栧厛鎴戜滑蹇呴』娓呮鐨勪竴鐐規(guī)槸String綾繪槸final綾誨瀷鐨勶紝鍥犳浣犱笉鍙互緇ф壙榪欎釜綾匯佷笉鑳戒慨鏀硅繖涓被銆傛垜浠嬌鐢⊿tring鐨勬椂鍊欓潪甯哥畝鍗曪紝閫氬父閮芥槸 String s = "hello"錛屼絾鏄疛ava API涓悓鏃舵彁渚涗簡(jiǎn)涓涓瀯閫犲嚱鏁頒負(fù)String(String s)錛屽洜姝や綘涔熷彲浠ヨ繖鏍蜂嬌鐢⊿tring s = new String("hello")錛屽浜庡悗闈㈣繖鏍峰垵濮嬪寲涓涓猄tring鐨勬柟寮忔槸涓嶆帹鑽愮殑錛屽洜涓簄ew鎿嶄綔絎︽剰鍛崇潃灝嗕細(xì)鍦╤eap涓婄敓鎴愪竴涓柊鐨勫璞★紝濡傛灉榪欐牱鐨勬搷浣滃彂鐢熷湪涓涓驚鐜腑錛岄偅涔堜唬浠鋒槸鎯ㄩ噸鐨勩傛瘮濡?br />
for(int i = 0;i<1000;i++)
{
String s = new String("hello");
}
榪欏皢浼?xì)鍒涘?000涓猄tring綾誨瀷鐨勫璞★紝鐢變簬String綾繪槸final鐨勶紝鍥犳榪欐牱鐨勬搷浣滀簨瀹炰笂鏄瘡嬈￠兘鐢熸垚浜?jiǎn)涓涓柊鐨凷tring瀵硅薄鐨勩傚鏋滀綘浣跨敤String s = "hello";閭ｄ箞灝卞彲浠ュ疄鐜板鐢ㄤ簡(jiǎn)錛屼負(fù)浠涔堝彲浠ュ鐢ㄥ憿錛屼笅闈細(xì)鏈夎В閲娿?/p>
褰撴垜浠嬌鐢?+"瀹炵幇涓茶仈鎿嶄綔鐨勬椂鍊欙紝姣斿String s = "hello"+"world";鍏跺疄鏄氳繃StringBuffer綾葷殑append()鏂規(guī)硶瀹炵幇鐨勶紝鏈鍚庤繑鍥濻tring緇檚銆傚鏋滄湁鍏磋叮鐨勮瘽錛屼綘鍙互鍐欎竴涓畝鍗曠殑渚嬪瓙錛岀劧鍚庣敤javap鐪嬬湅铏氭嫙鏈烘槸濡備綍宸ヤ綔鐨勩傚湪浣跨敤涓茶仈鐨勬椂鍊欐垜浠悓鏍峰簲璇ユ敞鎰廠(chǎng)tring鏄痜inal綾伙紝濡傛灉浣犻渶瑕佸嬈′覆鑱旀瘮濡傦細(xì)
String sql = "xxx";
sql = "xxxx";
sql = "ssssss";
閭ｄ箞涓轟簡(jiǎn)鎻愰珮鏁堢巼鑺傜渷絀洪棿錛屾垜浠簲璇ヨ嚜宸辯敤StringBuffer鏉ユ浛浠?+";
閫氬父瀵筍tring鐨勬瘮杈冩湁涓ょ鎯呭喌錛屼竴涓槸浣跨敤==錛屽彟涓涓槸浣跨敤equals()鏂規(guī)硶錛屾敞鎰?=鏄瀵硅薄鐨勫湴鍧榪涜姣旇緝鐨勶紝鑰孲tring涓殑 equals()鏂規(guī)硶鏄鐩栦簡(jiǎn)Object綾葷殑鏂規(guī)硶錛屽茍涓斿疄鐜頒負(fù)瀵筍tring瀵硅薄鐨勫唴瀹圭殑姣旇緝銆傛墍浠tring s1 = new String("hello");String s2 = new String("hello")錛屾垜浠s1鍜宻2榪涜涓婅堪姣旇緝鐨勬椂鍊欙紝鍓嶈呭簲璇ヨ繑鍥瀎alse,鍥犱負(fù)浣跨敤new鐢熸垚鐨勬槸涓や釜涓嶅悓鐨勫璞°傚悗鑰呭簲璇ヨ繑鍥?true鍥犱負(fù)浠栦滑鐨勫唴瀹規(guī)槸涓鏍風(fēng)殑錛岄兘鏄?hello"銆傞偅涔堝鏋滄垜浠繕鏈変竴涓猄tring s3 = "hello";浠栧拰s1鐨勬瘮杈冨簲璇ユ槸浠涔堟牱瀛愮殑鍛紝絳旀鏄痵1==s3涓篺alse錛宔quals鐨勬瘮杈冧綅true銆備簨瀹炰笂String綾繪槸緇存寔鐫涓涓?String姹犵殑錛岃繖涓睜鍒濆鍖栦負(fù)絀虹殑錛屽綋鎴戜滑String x = "hello"鐨勬椂鍊欙紝hello灝變細(xì)琚斁鍏ヨ繖涓睜涓紝褰撴垜浠啀嬈tring y = "hello"鐨勬椂鍊欙紝浠栭鍏堝幓媯(gè)鏌ユ睜涓槸鍚﹀瓨鍦ㄤ竴涓拰hello鍐呭涓鏍風(fēng)殑瀵硅薄錛屽鏋滃瓨鍦ㄧ殑璇濆氨浼?xì)鎶姌q欎釜寮曠敤榪斿洖緇檡,濡傛灉涓嶅瓨鍦ㄧ殑璇濓紝灝變細(xì)鍒涘緩涓涓茍鏀懼叆鍒版睜涓傝繖鏍峰氨瀹炵幇浜?jiǎn)澶嶇敤銆傚湪String鏈変竴涓柟娉昳ntern()浠栧彲浠ユ妸String鐨勫璞℃斁鍏ュ埌姹犲啿騫惰繑鍥炴睜涓殑瀵硅薄銆傚鏋滄垜浠 s1(String s1 = new String("hello"))璋冪敤intern,s1 = s1.intern()榪欐椂鍊欙紝鎴戜滑鍐嶆妸s1鍜宻3榪涜“==”鐨勫垽鏂紝浣犱細(xì)鍙戠幇緇撴灉榪斿洖true!
鐪嬩笅闈㈢殑渚嬪瓙
public class StringTest
{
public static void main(String[] args)
{
String s1 = "hello";
String s2 = new String("hello");
String s3 = new String("hello");
testString(s1,s2,s3);
s2 = s2.intern();
System.out.println("after s2.intern");
testString(s1,s2,s3);
}
private static void testString(String s1,String s2,String s3)
{
System.out.println("s1 = s2 is "+(s1==s2));
System.out.println("s2 = s3 is "+(s2==s3));
System.out.println("s1.equals(s2) is "+s1.equals(s2));
System.out.println("s2.equals(s3) is "+s2.equals(s3));
}
}
杈撳嚭緇撴灉涓?br />
s1 = s2 is false
s2 = s3 is false
s1.equals(s2) is true
s2.equals(s3) is true
after s2.intern
s1 = s2 is true
s2 = s3 is false
s1.equals(s2) is true
s2.equals(s3) is true
]]>
JAVA_HOME=C:\soft\jdk1.6.0
classpath=;%JAVA_HOME%\lib\tools.jar;%JAVA_HOME%\lib\dt.jar;
path=%JAVA_HOME%\bin;
java 鐗圭偣
1.闈㈠悜瀵硅薄錛?鍙Щ妞嶆э紝璺ㄥ鉤鍙幫紱3.鏀寔鍒嗗竷寮忕殑緗戠粶搴旂敤錛屽綰跨▼錛?.瀹夊叏鎬у拰鍋ュ．鎬э紱
涓澶勭紪璇戯紝澶勫榪愯錛?/p>
鍚嶈瘝瑙ｆ瀽 JDK java development kit
JavaEE-- java Enterprise Edition 浼佷笟鐗?br />
JavaSE-- java Stand Edition 鏍囧噯鐗?nbsp;
JavaME-- java Micro Edition 寰瀷鐗?br />
銆銆銆銆OCP--open(瀵規(guī)墿灞曞紑鍙?錛宑lose(瀵逛慨鏀瑰叧闂?
SUN鍏徃瀹樻柟緗戠珯http://java.sun.com
JDK鐨勫畨瑁呭強(qiáng)鐩綍緇撴瀯
-bin鐩綍錛氬瓨鏀懼彲鎵ц鏂囦歡
-lib鐩綍錛氬瓨鏀綣AVA鐨勭被搴撴枃浠訛紱
-include鐩綍錛氬瓨鏀劇敤浜庢湰鍦版柟娉曠殑鏂囦歡錛?br />
-demo鐩綍錛氬瓨鏀炬紨紺虹▼搴忥紱
-jre鐩綍錛氬瓨鏀綣ava榪愯鐜鏂囦歡錛?/p>
2. "System.out.println();"
System涓轟竴涓被錛坈lass錛?綾誨瓧孌靛拰綾繪柟娉曞墠蹇呴』鏈塻tatic 淇グ錛屽茍涓旇綾諱笉鑳借瀹炰緥鍖栵紝鍗充笉鑳借鍒涘緩鏂板璞★紱
out涓哄瓧孌?nbsp; 闈?rùn)鎬佹柟娉曢噷涓嶈兘鐢ㄩ潪闈?rùn)鎬佸彉閲?----瑙ｅ喅鏂規(guī)錛氬皢鍙橀噺鏀逛負(fù)闈?rùn)鎬佸彉閲忔垨鑰呭０鏄庝竴涓柊瀵硅薄鍐嶆璋冪敤鍙橀噺
3. Eclipse 綆鍗曞簲鐢?br /> 寤哄伐浣滅┖闂?→ 寤轟竴涓寘 → 寤虹被
4.鏍稿績(jī)鑳藉姏鍩瑰吇
鈶犺嚜瀛﹁兘鍔?nbsp; 涓誨姩鎬с佽嚜鎴戞帶鍒訛紙EQ錛?br />
鈶＄嫭绔嬭兘鍔?nbsp; 浜嬫儏==銆嬬嫭绔嬫濊冨垎鏋?-銆嬪嚭鐜伴棶棰橈紝瑙ｅ喅闂錛屾煡璧勬枡--銆?br />
鈶㈠洟闃熷悎浣滆兘鍔?鎶鏈瘑闆嗭紝娌熼?=銆嬫暍浜庯紝鏈夋晥娌熼?br />
鈶ｈ嫳鏂囬槄璇昏兘鍔?nbsp; 瀹樻柟鏂囨。錛圓PI 寮鍙戞枃妗ｏ紝瑙勮寖錛?br />
鈶ら珮璐ㄩ噺緙栫▼鑳藉姏 閫昏緫鎬?nbsp; 鍋ュ．鎬?鍙鎬?璁捐鍘熷垯錛堣緭鍏ヤ袱涓暟瀛楋肌鍜岋饑錛?#8220;+”錛?nbsp; 鎬ц兘
5.瀛︿範(fàn)鏂規(guī)硶
鈶犵瑪璁?br />
鈶¤蹇嗭細(xì)澶у鐨勭悊瑙?涓鐨勮蹇?br />
鈶㈠涔?fàn)鏃堕椷_(dá)細(xì)8鐐瑰埌鍗佷竴鐐?br />
鈶ｈ嫳鏂囪蹇?br />
6.璇█鐨勬紨鍙?nbsp;
鈶犻渶姹傜殑鍙樺寲
鈶＄紪紼嬭壓鏈?br />
7.璁捐鏂拌璦
鈶犳槗鐢ㄦ?br />
鈶″畨鍏ㄦ?br />
鈶㈡晥鐜囨ч珮
鈶ｇǔ瀹氭?br />
鈶ゅ彲鎵╁睍鎬?br />
8.鏁版嵁榪愮畻
琚櫎鏁伴櫎浠ラ櫎鏁?nbsp; 6/5=1錛涳紙鍙栨暣錛?nbsp; 5%6=5錛涳紙鍙栦綑錛?br />
a+=b;鐩稿綋浜巃=a+b; 渚濇綾繪帹錛屼箻娉曪紝闄ゆ硶錛屽噺娉?br />
闂茬潃娌′簨騫詫紝鎶婁互鍓嶇殑涓滆タ鍐欏啓
]]>
InputStream綾繪槸鎵鏈夎緭鍏ユ祦鐨勭埗綾伙紝瀹冩槸涓涓娊璞＄被錛屼笉鑳借瀹炰緥鍖栥傚畠鎻愪緵浜?jiǎn)涓緋誨垪鍜岃鍙栨暟鎹湁鍏崇殑鏂規(guī)硶銆?br /> int read(),int read(byte[] b)浠庢暟鎹簮璇誨彇鏁版嵁
void close() 褰撳畬鎴愯鎿嶄綔鍚庯紝搴旇鍏抽棴杈撳叆嫻併?br /> 甯哥敤鍒扮殑瀛愮被,ByteArrayInputStream瀛楄妭鏁扮粍杈撳叆嫻? FileInputStream鏂囦歡杈撳叆嫻? StringBufferStream瀛楃涓茬紦鍐茶緭鍏ユ祦, ObjectInputStream瀵硅薄杈撳叆嫻? FilterInputStream榪囨護(hù)杈撳叆嫻侊紝鍏朵腑榪囨護(hù)杈撳叆嫻佷腑涓昏鐢ㄥ埌鐨勬槸BufferedInputStream鍜孌ataInputStream錛堝疄鐜頒簡(jiǎn)DataInput鎺ュ彛錛岀敤浜庤鍙栧熀鏈暟鎹被鍨嬶紝濡俰nt 銆乴ong銆乫loat銆乨ouble銆乥oolean絳夛級(jí)
鏈夎緭鍏ユ祦錛屽氨鏈夌浉搴旂殑杈撳嚭嫻侊紝涔熷氨鏄灝唅ntput鏀逛負(fù)output銆備絾鏄湪榪欓噷瑕佺潃閲嶆彁鍒扮殑鏄殢鏈鴻鍙栨枃浠剁被RandomAccessFile鍜屽璞℃祦Object銆傛湰浜哄鍓嶈呮病鏈夊灝戝皾璇曪紝浣嗗鍚庤呮垜灝卞彲浠ュ垎浜垜鐨勪竴鐐圭煡璇嗐傚璞℃祦鐢ㄥ埌浜?jiǎn)瀵硅薄鐨勫簭鍒楀寲鍜屽弽搴忓垪鍖栧Q屽簭鍒楀寲鐨勬剰鎬濆氨鏄妸瀵硅薄鍐欏埌涓涓緭鍏ユ祦涓紱鍙嶅簭鍒楀寲鏄粠涓涓緭鍏ユ祦涓鍙栦竴涓璞°傚鏋滆閲囩敤瀵硅薄杈撳叆杈撳嚭嫻侊紝閭ｄ箞榪欎釜瀵硅薄鐨勭被蹇呴』瀹炵幇鍙簭鍒楀寲鎺ュ彛銆傚皢瀵硅薄涔熷氨鏄璞＄殑鎴愬憳鍙橀噺浣滀負(fù)鏁翠綋錛屽啓鍒版祦涓瓨鍌ㄥ埌鏂囦歡閲岃竟銆傛垨鑰呭氨鏄妸瀵硅薄鏀懼埌鏁扮粍閲岃竟錛屽皢榪欎釜瀵硅薄鏁扮粍瀛樺叆鍒板悓涓涓枃浠朵腑錛屽鍏惰繘琛屾搷浣滐紝鍦ㄦ病鏈夋暟鎹簱鐨勬儏鍐典笅錛屾垜涓漢璁や負(fù)榪欐槸鏈濂界殑淇濆瓨瀵硅薄淇℃伅鏂規(guī)硶銆?br /> 璇ョ潯瑙変簡(jiǎn)錛屽厛鍐欏埌榪欓噷錛屾槑澶╁皢鎴戞墍鍋氱殑瀵硅薄嫻佷唬鐮佸啓鍒頒笂杈癸紝渚涘ぇ瀹跺弬鑰冧氦嫻?
]]>
鍦ㄥ垱寤篔ava鏁扮粍鏃訛紝蹇呴』鏄庣‘鎸囧畾鏁扮粍闀垮害錛屾暟緇勪竴鏃﹀垱寤猴紝鍏墮暱搴﹀氨涓嶈兘琚敼鍙樸備負(fù)浜?jiǎn)鋴山E嬪簭鑳芥柟渚跨殑瀛樺偍鍜屾搷綰墊暟鐩笉鍥哄畾鐨勪竴緇勬暟鎹紝JDK綾誨簱鎻愪緵浜?jiǎn)Java闆嗗悎錛屾墍鏈塉ava闆嗗悎綾婚兘浣嶄簬java.util鍖呬腑銆?br /> 1銆丼et錛堥泦錛夛細(xì)闆嗗悎涓殑瀵硅薄涓嶆寜鐗瑰畾鏂瑰紡鎺掑簭錛屽茍涓旀病鏈夐噸澶嶅璞°俆reeSet錛孒ashSet
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