瑕佷笅璧跺揩錛?
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http://tools.google.com/pinyin/index.html
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http://www.harding.edu/USER/fmccown/WWW/java1_5_csharp_comparison.html#comments
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絎竴錛岃皥璋?/span> final 錛?/span> finally 錛?/span> finalize 鐨勫尯鍒紵
Final 錛氫慨楗扮錛堝叧閿瓧錛夊鏋滀竴涓被琚０鏄庝負 final 錛屾剰鍛崇潃瀹冧笉鑳藉啀媧劇敓鍑烘柊鐨勫瓙綾伙紝
涓嶈兘浣滀負鐖剁被琚戶鎵褲€傚洜姝や竴涓被涓嶈兘鏃㈣澹版槑涓?/span> abstract 鐨勶紝鍙堣澹版槑涓?/span> final 鐨勩€傚皢鍙?/span>
閲忔垨鏂規硶澹版槑涓?/span> final 錛屽彲浠ヤ繚璇佸畠浠湪浣跨敤涓笉琚敼鍙樸€傝澹版槑涓?/span> final 鐨勫彉閲忓繀欏誨湪澹?/span>
鏄庢椂緇欏畾鍒濆€鹼紝鑰屽湪浠ュ悗鐨勫紩鐢ㄤ腑鍙兘璇誨彇錛屼笉鍙慨鏀廣€傝澹版槑涓?/span> final 鐨勬柟娉曚篃鍚屾牱鍙兘
浣跨敤錛屼笉鑳介噸杞?/span>
finally 錛熷啀寮傚父澶勭悊鏃舵彁渚?/span> finally{} 鍧楁潵鎵ц浠諱綍娓呴櫎鎿嶄綔銆傚鏋滄姏鍑轟竴涓紓甯革紝閭ｄ箞
鐩稿尮閰嶇殑 catch 瀛愬彞灝變細鎵ц錛岀劧鍚庢帶鍒跺氨浼氳繘鍏?/span> finally 鍧楋紙濡傛灉鏈夌殑璇濓級銆?/span>
finalize 錛氭柟娉曞悕銆?/span> Java 鎶€鏈厑璁鎬嬌鐢?/span> finalize 錛堬級鏂規硶鍦ㄥ瀮鍦炬敹闆嗗櫒灝嗗璞′粠鍐呭瓨涓?/span>
娓呴櫎鍑哄幓涔嬪墠鍋氬繀瑕佺殑娓呯悊宸ヤ綔銆傝繖涓柟娉曟槸鐢卞瀮鍦炬敹闆嗗櫒鍦ㄧ‘瀹氳繖涓璞℃病鏈夎寮曠敤鏃?/span>
瀵硅繖涓璞¤皟鐢ㄧ殑銆傚畠鏄湪 Object 綾諱腑瀹氫箟鐨勶紝鍥犳鎵€鏈夌殑綾婚兘緇ф壙浜嗗畠銆傚瓙綾昏鐩?/span> fi
nalize 錛堬級鏂規硶浠ユ暣鐞嗙郴緇熻祫婧愭垨鑰呮墽琛屽叾浠栨竻鐞嗗伐浣溿€?/span> finalize 錛堬級 鏂規硶鏄湪鍨冨溇鏀墮泦
鍣ㄥ垹闄ゅ璞′箣鍓嶅榪欎釜瀵硅薄璋冪敤鐨勩€?/span>
絎簩錛?/span> Anonymous Inner Class 錛堝尶鍚嶅唴閮ㄧ被錛?/span> 鏄惁鍙互 extends 錛堢戶鎵匡級鍏跺畠綾伙紝鏄惁
鍙互 implements 錛堝疄鐜幫級 interface 錛堟帴鍙ｏ級錛?/span>
鍖垮悕鐨勫唴閮ㄧ被鏄病鏈夊悕瀛楃殑鍐呴儴綾匯€備笉鑳?/span> extends 錛堢戶鎵匡級 鍏跺畠綾伙紝浣嗕竴涓唴閮ㄧ被鍙互浣?/span>
涓轟竴涓帴鍙ｏ紝鐢卞彟涓€涓唴閮ㄧ被瀹炵幇銆?/span>
絎笁錛?/span> Static Nested Class 鍜?/span> Inner Class 鐨勪笉鍚岋紝璇村緱瓚婂瓚婂ソ錛堥潰璇曢鏈夌殑寰堢緇?/span>
錛夛紵
Nested Class 錛堜竴鑸槸 C++ 鐨勮娉曪級錛?/span> Inner Class 錛堜竴鑸槸 JAVA 鐨勮娉曪級銆?/span> Java 鍐呴儴綾?/span>
涓?/span> C++ 宓屽綾繪渶澶х殑涓嶅悓灝卞湪浜庢槸鍚︽湁鎸囧悜澶栭儴鐨勫紩鐢ㄤ笂銆?/span>
鍏蜂綋鍙 http 錛?/span> //www.frontfree.net/articles/services/view.asp 錛?/span> id=704&page=1
娉細 闈欐€佸唴閮ㄧ被錛?/span> Inner Class 錛夋剰鍛崇潃 1 鍒涘緩涓€涓?/span> static 鍐呴儴綾葷殑瀵硅薄錛屼笉闇€瑕佷竴涓閮?/span>
綾誨璞★紝 2 涓嶈兘浠庝竴涓?/span> static 鍐呴儴綾葷殑涓€涓璞¤闂竴涓閮ㄧ被瀵硅薄銆?/span>
絎洓錛?/span> & 鍜?/span> && 鐨勫尯鍒紵
& 鏄綅榪愮畻絎︺€?/span> && 鏄竷灝旈€昏緫榪愮畻絎︺€?/span>
絎簲錛?/span> HashMap 鍜?/span> Hashtable 鐨勫尯鍒紵
閮藉睘浜?/span> Map 鎺ュ彛鐨勭被錛屽疄鐜頒簡灝嗘儫涓€閿槧灝勫埌鐗瑰畾鐨勫€間笂銆?/span>
HashMap 綾繪病鏈夊垎綾繪垨鑰呮帓搴忋€傚畠鍏佽涓€涓?/span> null 閿拰澶氫釜 null 鍊箋€?/span>
Hashtable 綾諱技浜?/span> HashMap 錛屼絾鏄笉鍏佽 null 閿拰 null 鍊箋€傚畠涔熸瘮 HashMap 鎱紝鍥犱負
瀹冩槸鍚屾鐨勩€?/span>
絎叚錛?/span> Collection 鍜?/span> Collections 鐨勫尯鍒紵
Collections 鏄釜 java.util 涓嬬殑綾伙紝瀹冨寘鍚湁鍚勭鏈夊叧闆嗗悎鎿嶄綔鐨勯潤鎬佹柟娉曘€?/span>
Collection 鏄釜 java.util 涓嬬殑鎺ュ彛錛屽畠鏄悇縐嶉泦鍚堢粨鏋勭殑鐖舵帴鍙ｃ€?/span>
絎竷錛屼粈涔堟椂鍊欑敤 assert 錛?/span>
鏂█鏄竴涓寘鍚竷灝旇〃杈懼紡鐨勮鍙ワ紝鍦ㄦ墽琛岃繖涓鍙ユ椂鍋囧畾璇ヨ〃杈懼紡涓?/span> true 銆傚鏋滆〃杈懼紡
璁＄畻涓?/span> false 錛岄偅涔堢郴緇熶細鎶ュ憡涓€涓?/span>
AssertionError 銆傚畠鐢ㄤ簬璋冭瘯鐩殑錛?/span>
assert(a > 0); // throws an AssertionError if a <= 0 錛?/span>
鏂█鍙互鏈変袱縐嶅艦寮忥細
assert Expression1 ;
assert Expression1 : Expression2 ;
Expression1 搴旇鎬繪槸浜х敓涓€涓竷灝斿€箋€?/span>
Expression2 鍙互鏄緱鍑轟竴涓€肩殑浠繪剰琛ㄨ揪寮忋€傝繖涓€肩敤浜庣敓鎴愭樉紺烘洿澶氳皟璇曚俊鎭殑 Str
ing 娑堟伅銆?/span>
鏂█鍦ㄩ粯璁ゆ儏鍐典笅鏄鐢ㄧ殑銆傝鍦ㄧ紪璇戞椂鍚敤鏂█錛岄渶瑕佷嬌鐢?/span> source 1.4 鏍囪錛?/span>
javac -source 1.4 Test.java
瑕佸湪榪愯鏃跺惎鐢ㄦ柇璦€錛屽彲浣跨敤 -enableassertions 鎴栬€?/span> -ea 鏍囪銆?/span>
瑕佸湪榪愯鏃墮€夋嫨紱佺敤鏂█錛屽彲浣跨敤 -da 鎴栬€?/span> -disableassertions 鏍囪銆?/span>
瑕佺郴緇熺被涓惎鐢ㄦ柇璦€錛屽彲浣跨敤 -esa 鎴栬€?/span> -dsa 鏍囪銆傝繕鍙互鍦ㄥ寘鐨勫熀紜€涓婂惎鐢ㄦ垨鑰呯鐢?/span>
鏂█銆?/span>
鍙互鍦ㄩ璁℃甯告儏鍐典笅涓嶄細鍒拌揪鐨勪換浣曚綅緗笂鏀劇疆鏂█銆傛柇璦€鍙互鐢ㄤ簬楠岃瘉浼犻€掔粰縐佹湁鏂?/span>
娉曠殑鍙傛暟銆備笉榪囷紝鏂█涓嶅簲璇ョ敤浜庨獙璇佷紶閫掔粰鍏湁鏂規硶鐨勫弬鏁幫紝鍥犱負涓嶇鏄惁鍚敤浜嗘柇璦€
錛屽叕鏈夋柟娉曢兘蹇呴』媯€鏌ュ叾鍙傛暟銆備笉榪囷紝鏃㈠彲浠ュ湪鍏湁鏂規硶涓紝涔熷彲浠ュ湪闈炲叕鏈夋柟娉曚腑鍒╃敤
鏂█嫻嬭瘯鍚庣疆鏉′歡銆傚彟澶栵紝鏂█涓嶅簲璇ヤ互浠諱綍鏂瑰紡鏀瑰彉紼嬪簭鐨勭姸鎬併€?/span>
絎叓錛?/span> GC 鏄粈涔?/span> ? 涓轟粈涔堣鏈?/span> GC? ( 鍩虹 ) 錛?/span>
GC 鏄瀮鍦炬敹闆嗗櫒銆?/span> Java 紼嬪簭鍛樹笉鐢ㄦ媴蹇冨唴瀛樼鐞嗭紝鍥犱負鍨冨溇鏀墮泦鍣ㄤ細鑷姩榪涜綆＄悊銆傝璇?/span>
姹傚瀮鍦炬敹闆嗭紝鍙互璋冪敤涓嬮潰鐨勬柟娉曚箣涓€錛?/span>
System.gc()
Runtime.getRuntime().gc()
絎節錛?/span> String s = new String("xyz"); 鍒涘緩浜嗗嚑涓?/span> String Object?
涓や釜瀵硅薄錛屼竴涓槸 “xyx”, 涓€涓槸鎸囧悜 “xyx” 鐨勫紩鐢ㄥ璞?/span> s 銆?/span>
絎崄錛?/span> Math.round(11.5) 絳夋柤澶氬皯 ? Math.round(-11.5) 絳夋柤澶氬皯 ?
Math.round(11.5) 榪斿洖錛?/span> long 錛?/span> 12 錛?/span> Math.round(-11.5) 榪斿洖錛?/span> long 錛?/span> -11;
絎崄涓€錛?/span> short s1 = 1; s1 = s1 + 1; 鏈変粈涔堥敊 ? short s1 = 1; s1 += 1; 鏈変粈涔堥敊 ?
short s1 = 1; s1 = s1 + 1; 鏈夐敊錛?/span> s1 鏄?/span> short 鍨嬶紝 s1+1 鏄?/span> int 鍨?/span> , 涓嶈兘鏄懼紡杞寲涓?/span> short 鍨?/span>
銆傚彲淇敼涓?/span> s1 =(short)(s1 + 1) 銆?/span> short s1 = 1; s1 += 1 姝ｇ‘銆?/span>
絎崄浜岋紝 sleep() 鍜?/span> wait() 鏈変粈涔堝尯鍒?/span> ?
鎼炵嚎紼嬬殑鏈€鐖?/span> sleep() 鏂規硶鏄嬌綰跨▼鍋滄涓€孌墊椂闂寸殑鏂規硶銆傚湪 sleep 鏃墮棿闂撮殧鏈熸弧鍚庯紝綰?/span>
紼嬩笉涓€瀹氱珛鍗蟲仮澶嶆墽琛屻€傝繖鏄洜涓哄湪閭ｄ釜鏃跺埢錛屽叾瀹冪嚎紼嬪彲鑳芥鍦ㄨ繍琛岃€屼笖娌℃湁琚皟搴︿負
鏀懼純鎵ц錛岄櫎闈?/span> (a)“ 閱掓潵 ” 鐨勭嚎紼嬪叿鏈夋洿楂樼殑浼樺厛綰э紝 (b) 姝ｅ湪榪愯鐨勭嚎紼嬪洜涓哄叾瀹冨師鍥?/span>
鑰岄樆濉炪€?/span>
wait() 鏄嚎紼嬩氦浜掓椂錛屽鏋滅嚎紼嬪涓€涓悓姝ュ璞?/span> x 鍙戝嚭涓€涓?/span> wait() 璋冪敤錛岃綰跨▼浼氭殏鍋滄墽
琛岋紝琚皟瀵硅薄榪涘叆絳夊緟鐘舵€侊紝鐩村埌琚敜閱掓垨絳夊緟鏃墮棿鍒般€?/span>
絎崄涓夛紝 Java 鏈夋病鏈?/span> goto?
Goto?java 涓殑淇濈暀瀛楋紝鐜板湪娌℃湁鍦?/span> java 涓嬌鐢ㄣ€?/span>
絎崄鍥涳紝鏁扮粍鏈夋病鏈?/span> length() 榪欎釜鏂規硶 ? String 鏈夋病鏈?/span> length() 榪欎釜鏂規硶錛?/span>
鏁扮粍娌℃湁 length() 榪欎釜鏂規硶錛屾湁 length 鐨勫睘鎬с€?/span>
String 鏈夋湁 length() 榪欎釜鏂規硶銆?/span>
絎崄浜旓紝 Overload 鍜?/span> Override 鐨勫尯鍒€?/span> Overloaded 鐨勬柟娉曟槸鍚﹀彲浠ユ敼鍙樿繑鍥炲€肩殑綾誨瀷 ?
鏂規硶鐨勯噸鍐?/span> Overriding 鍜岄噸杞?/span> Overloading 鏄?/span> Java 澶氭€佹€х殑涓嶅悓琛ㄧ幇銆傞噸鍐?/span> Overriding 鏄埗
綾諱笌瀛愮被涔嬮棿澶氭€佹€х殑涓€縐嶈〃鐜幫紝閲嶈澆 Overloading 鏄竴涓被涓鎬佹€х殑涓€縐嶈〃鐜般€傚鏋滃湪
瀛愮被涓畾涔夋煇鏂規硶涓庡叾鐖剁被鏈夌浉鍚岀殑鍚嶇О鍜屽弬鏁幫紝鎴戜滑璇磋鏂規硶琚噸鍐?/span> (Overriding) 銆傚瓙
綾葷殑瀵硅薄浣跨敤榪欎釜鏂規硶鏃訛紝灝嗚皟鐢ㄥ瓙綾諱腑鐨勫畾涔夛紝瀵瑰畠鑰岃█錛岀埗綾諱腑鐨勫畾涔夊鍚岃 “ 灞忚斀
” 浜嗐€傚鏋滃湪涓€涓被涓畾涔変簡澶氫釜鍚屽悕鐨勬柟娉曪紝瀹冧滑鎴栨湁涓嶅悓鐨勫弬鏁頒釜鏁版垨鏈変笉鍚岀殑鍙傛暟
綾誨瀷錛屽垯縐頒負鏂規硶鐨勯噸杞?/span> (Overloading) 銆?/span> Overloaded 鐨勬柟娉曟槸鍙互鏀瑰彉榪斿洖鍊肩殑綾誨瀷銆?/span>
絎崄鍏紝 Set 閲岀殑鍏冪礌鏄笉鑳介噸澶嶇殑錛岄偅涔堢敤浠€涔堟柟娉曟潵鍖哄垎閲嶅涓庡惁鍛?/span> ? 鏄敤 == 榪樻槸 equ
als()? 瀹冧滑鏈変綍鍖哄埆 ?
Set 閲岀殑鍏冪礌鏄笉鑳介噸澶嶇殑錛岄偅涔堢敤 iterator() 鏂規硶鏉ュ尯鍒嗛噸澶嶄笌鍚︺€?/span> equals() 鏄垽璇諱袱涓?/span>
Set 鏄惁鐩哥瓑銆?/span>
equals() 鍜?/span> == 鏂規硶鍐沖畾寮曠敤鍊兼槸鍚︽寚鍚戝悓涓€瀵硅薄 equals() 鍦ㄧ被涓瑕嗙洊錛屼負鐨勬槸褰撲袱涓垎
紱葷殑瀵硅薄鐨勫唴瀹瑰拰綾誨瀷鐩擱厤鐨勮瘽錛岃繑鍥炵湡鍊箋€?/span>
絎崄涓冿紝緇欐垜涓€涓綘鏈€甯歌鍒扮殑 runtime exception 錛?/span>
ArithmeticException, ArrayStoreException, BufferOverflowException,
BufferUnderflowException, CannotRedoException,
CannotUndoException, ClassCastException, CMMException,
ConcurrentModificationException,
DOMException, EmptyStackException, IllegalArgumentException,
IllegalMonitorStateException,
IllegalPathStateException, IllegalStateException,
ImagingOpException,
IndexOutOfBoundsException, MissingResourceException,
NegativeArraySizeException, NoSuchElementException,
NullPointerException, ProfileDataException, ProviderException,
RasterFormatException, SecurityException, SystemException,
UndeclaredThrowableException,
UnmodifiableSetException, UnsupportedOperationException
絎崄鍏紝 error 鍜?/span> exception 鏈変粈涔堝尯鍒?/span> ?
error 琛ㄧず鎭㈠涓嶆槸涓嶅彲鑳戒絾寰堝洶闅劇殑鎯呭喌涓嬬殑涓€縐嶄弗閲嶉棶棰樸€傛瘮濡傝鍐呭瓨婧㈠嚭銆備笉鍙兘
鎸囨湜紼嬪簭鑳藉鐞嗚繖鏍風殑鎯呭喌
exception 琛ㄧず涓€縐嶈璁℃垨瀹炵幇闂銆備篃灝辨槸璇達紝瀹冭〃紺哄鏋滅▼搴忚繍琛屾甯革紝浠庝笉浼氬彂鐢?/span>
鐨勬儏鍐點€?/span>
絎崄涔濓紝 List, Set, Map 鏄惁緇ф壙鑷?/span> Collection 鎺ュ彛 ?
List 錛?/span> Set 鏄?/span>
Map 涓嶆槸
絎簩鍗侊紝 abstract class 鍜?/span> interface 鏈変粈涔堝尯鍒?/span> ?
澹版槑鏂規硶鐨勫瓨鍦ㄨ€屼笉鍘誨疄鐜板畠鐨勭被琚彨鍋氭娊璞＄被錛?/span> abstract class 錛夛紝瀹冪敤浜庤鍒涘緩涓€涓?/span>
浣撶幇鏌愪簺鍩烘湰琛屼負鐨勭被錛屽茍涓鴻綾誨０鏄庢柟娉曪紝浣嗕笉鑳藉湪璇ョ被涓疄鐜拌綾葷殑鎯呭喌銆備笉鑳藉垱寤?/span>
abstract 綾葷殑瀹炰緥銆傜劧鑰屽彲浠ュ垱寤轟竴涓彉閲忥紝鍏剁被鍨嬫槸涓€涓娊璞＄被錛屽茍璁╁畠鎸囧悜鍏蜂綋瀛愮被
鐨勪竴涓疄渚嬨€備笉鑳芥湁鎶借薄鏋勯€犲嚱鏁版垨鎶借薄闈欐€佹柟娉曘€?/span> Abstract 綾葷殑瀛愮被涓哄畠浠埗綾諱腑鐨勬墍
鏈夋娊璞℃柟娉曟彁渚涘疄鐜幫紝鍚﹀垯瀹冧滑涔熸槸鎶借薄綾諱負銆傚彇鑰屼唬涔嬶紝鍦ㄥ瓙綾諱腑瀹炵幇璇ユ柟娉曘€傜煡閬撳叾
琛屼負鐨勫叾瀹冪被鍙互鍦ㄧ被涓疄鐜拌繖浜涙柟娉曘€?/span>
鎺ュ彛錛?/span> interface 錛夋槸鎶借薄綾葷殑鍙樹綋銆傚湪鎺ュ彛涓紝鎵€鏈夋柟娉曢兘鏄娊璞＄殑銆傚緇ф壙鎬у彲閫氳繃瀹?/span>
鐜拌繖鏍風殑鎺ュ彛鑰岃幏寰椼€傛帴鍙ｄ腑鐨勬墍鏈夋柟娉曢兘鏄娊璞＄殑錛屾病鏈変竴涓湁紼嬪簭浣撱€傛帴鍙ｅ彧鍙互瀹?/span>
涔?/span> static final 鎴愬憳鍙橀噺銆傛帴鍙ｇ殑瀹炵幇涓庡瓙綾葷浉浼鹼紝闄や簡璇ュ疄鐜扮被涓嶈兘浠庢帴鍙ｅ畾涔変腑緇ф壙
琛屼負銆傚綋綾誨疄鐜扮壒孌婃帴鍙ｆ椂錛屽畠瀹氫箟錛堝嵆灝嗙▼搴忎綋緇欎簣錛夋墍鏈夎繖縐嶆帴鍙ｇ殑鏂規硶銆傜劧鍚庯紝瀹?/span>
鍙互鍦ㄥ疄鐜頒簡璇ユ帴鍙ｇ殑綾葷殑浠諱綍瀵硅薄涓婅皟鐢ㄦ帴鍙ｇ殑鏂規硶銆傜敱浜庢湁鎶借薄綾伙紝瀹冨厑璁鎬嬌鐢ㄦ帴鍙?/span>
鍚嶄綔涓哄紩鐢ㄥ彉閲忕殑綾誨瀷銆傞€氬父鐨勫姩鎬佽仈緙栧皢鐢熸晥銆傚紩鐢ㄥ彲浠ヨ漿鎹㈠埌鎺ュ彛綾誨瀷鎴栦粠鎺ュ彛綾誨瀷
杞崲錛?/span> instanceof 榪愮畻絎﹀彲浠ョ敤鏉ュ喅瀹氭煇瀵硅薄鐨勭被鏄惁瀹炵幇浜嗘帴鍙ｃ€?/span>
絎簩鍗佷竴錛?/span> abstract 鐨?/span> method 鏄惁鍙悓鏃舵槸 static, 鏄惁鍙悓鏃舵槸 native 錛屾槸鍚﹀彲鍚屾椂鏄?/span> s
ynchronized?
閮戒笉鑳?/span>
絎簩鍗佷簩錛屾帴鍙ｆ槸鍚﹀彲緇ф壙鎺ュ彛 ? 鎶借薄綾繪槸鍚﹀彲瀹炵幇 (implements) 鎺ュ彛 ? 鎶借薄綾繪槸鍚﹀彲緇?/span>
鎵垮疄浣撶被 (concrete class)?
鎺ュ彛鍙互緇ф壙鎺ュ彛銆傛娊璞＄被鍙互瀹炵幇 (implements) 鎺ュ彛錛屾娊璞＄被鏄惁鍙戶鎵垮疄浣撶被錛屼絾鍓?/span>
鎻愭槸瀹炰綋綾誨繀欏繪湁鏄庣‘鐨勬瀯閫犲嚱鏁般€?/span>
絎簩鍗佷笁錛屽惎鍔ㄤ竴涓嚎紼嬫槸鐢?/span> run() 榪樻槸 start()?
鍚姩涓€涓嚎紼嬫槸璋冪敤 start() 鏂規硶錛屼嬌綰跨▼鎵€浠ｈ〃鐨勮櫄鎷熷鐞嗘満澶勪簬鍙繍琛岀姸鎬侊紝榪欐剰鍛崇潃
瀹冨彲浠ョ敱 JVM 璋冨害騫舵墽琛屻€傝繖騫朵笉鎰忓懗鐫€綰跨▼灝變細绔嬪嵆榪愯銆?/span> run() 鏂規硶鍙互浜х敓蹇呴』閫€鍑?/span>
鐨勬爣蹇楁潵鍋滄涓€涓嚎紼嬨€?/span>
絎簩鍗佸洓錛屾瀯閫犲櫒 Constructor 鏄惁鍙 override?
鏋勯€犲櫒 Constructor 涓嶈兘琚戶鎵匡紝鍥犳涓嶈兘閲嶅啓 Overriding 錛屼絾鍙互琚噸杞?/span> Overloading 銆?/span>
絎簩鍗佷簲錛屾槸鍚﹀彲浠ョ戶鎵?/span> String 綾?/span> ?
String 綾繪槸 final 綾繪晠涓嶅彲浠ョ戶鎵褲€?/span>
絎簩鍗佸叚錛屽綋涓€涓嚎紼嬭繘鍏ヤ竴涓璞＄殑涓€涓?/span> synchronized 鏂規硶鍚庯紝鍏跺畠綰跨▼鏄惁鍙繘鍏ユ
瀵硅薄鐨勫叾瀹冩柟娉?/span> ?
涓嶈兘錛屼竴涓璞＄殑涓€涓?/span> synchronized 鏂規硶鍙兘鐢變竴涓嚎紼嬭闂€?/span>
絎簩鍗佷竷錛?/span> try {} 閲屾湁涓€涓?/span> return 璇彞錛岄偅涔堢揣璺熷湪榪欎釜 try 鍚庣殑 finally {} 閲岀殑 code 浼氫笉
浼氳鎵ц錛屼粈涔堟椂鍊欒鎵ц錛屽湪 return 鍓嶈繕鏄悗 ?
浼氭墽琛岋紝鍦?/span> return 鍓嶆墽琛屻€?/span>
絎簩鍗佸叓錛岀紪紼嬮 : 鐢ㄦ渶鏈夋晥鐜囩殑鏂規硶綆楀嚭 2 涔樹互 8 絳夋柤鍑?/span> ?
鏈?/span> C 鑳屾櫙鐨勭▼搴忓憳鐗瑰埆鍠滄闂繖縐嶉棶棰樸€?/span>
2 << 3
絎簩鍗佷節錛屼袱涓璞″€肩浉鍚?/span> (x.equals(y) == true) 錛屼絾鍗村彲鏈変笉鍚岀殑 hash code 錛岃繖鍙ヨ瘽
瀵逛笉瀵?/span> ?
涓嶅錛屾湁鐩稿悓鐨?/span> hash code 銆?/span>
絎笁鍗侊紝褰撲竴涓璞¤褰撲綔鍙傛暟浼犻€掑埌涓€涓柟娉曞悗錛屾鏂規硶鍙敼鍙樿繖涓璞＄殑灞炴€э紝騫跺彲
榪斿洖鍙樺寲鍚庣殑緇撴灉錛岄偅涔堣繖閲屽埌搴曟槸鍊間紶閫掕繕鏄紩鐢ㄤ紶閫?/span> ?
鏄€間紶閫掋€?/span> Java 緙栫▼璇█鍙敱鍊間紶閫掑弬鏁般€傚綋涓€涓璞″疄渚嬩綔涓轟竴涓弬鏁拌浼犻€掑埌鏂規硶涓?/span>
鏃訛紝鍙傛暟鐨勫€煎氨鏄璇ュ璞＄殑寮曠敤銆傚璞＄殑鍐呭鍙互鍦ㄨ璋冪敤鐨勬柟娉曚腑鏀瑰彉錛屼絾瀵硅薄鐨勫紩
鐢ㄦ槸姘歌繙涓嶄細鏀瑰彉鐨勩€?/span>
絎笁鍗佷竴錛?/span> swtich 鏄惁鑳戒綔鐢ㄥ湪 byte 涓婏紝鏄惁鑳戒綔鐢ㄥ湪 long 涓婏紝鏄惁鑳戒綔鐢ㄥ湪 String 涓?/span> ?
switch 錛?/span> expr1 錛変腑錛?/span> expr1 鏄竴涓暣鏁拌〃杈懼紡銆傚洜姝や紶閫掔粰 switch 鍜?/span> case 璇彞鐨勫弬鏁?/span>
搴旇鏄?/span> int 銆?/span> short 銆?/span> char 鎴栬€?/span> byte 銆?/span> long,string 閮戒笉鑳戒綔鐢ㄤ簬 swtic
h 銆?/span>
絎笁鍗佷簩錛岀紪紼嬮 : 鍐欎竴涓?/span> Singleton 鍑烘潵錛?/span>
Singleton 妯″紡涓昏浣滅敤鏄繚璇佸湪 Java 搴旂敤紼嬪簭涓紝涓€涓被 Class 鍙湁涓€涓疄渚嬪瓨鍦ㄣ€?/span>
涓€鑸?/span> Singleton 妯″紡閫氬父鏈夊嚑縐嶇褰㈠紡 :
絎竴縐嶅艦寮?/span> : 瀹氫箟涓€涓被錛屽畠鐨勬瀯閫犲嚱鏁頒負 private 鐨勶紝瀹冩湁涓€涓?/span> static 鐨?/span> private 鐨勮綾?/span>
鍙橀噺錛屽湪綾誨垵濮嬪寲鏃跺疄渚嬭瘽錛岄€氳繃涓€涓?/span> public 鐨?/span> getInstance 鏂規硶鑾峰彇瀵瑰畠鐨勫紩鐢?/span> , 緇ц€岃皟
鐢ㄥ叾涓殑鏂規硶銆?/span>
public class Singleton {
private Singleton(){}
// 鍦ㄨ嚜宸卞唴閮ㄥ畾涔夎嚜宸變竴涓疄渚嬶紝鏄笉鏄緢濂囨€紵
// 娉ㄦ剰榪欐槸 private 鍙緵鍐呴儴璋冪敤
private static Singleton instance = new Singleton();
// 榪欓噷鎻愪緵浜嗕竴涓緵澶栭儴璁塊棶鏈?/span> class 鐨勯潤鎬佹柟娉曪紝鍙互鐩存帴璁塊棶
public static Singleton getInstance() {
銆€銆€ return instance; 銆€銆€
}
}
絎簩縐嶅艦寮?/span> :
public class Singleton {
private static Singleton instance = null;
public static synchronized Singleton getInstance() {
// 榪欎釜鏂規硶姣斾笂闈㈡湁鎵€鏀硅繘錛屼笉鐢ㄦ瘡嬈￠兘榪涜鐢熸垚瀵硅薄錛屽彧鏄涓€嬈°€€銆€銆€ 銆€
// 浣跨敤鏃剁敓鎴愬疄渚嬶紝鎻愰珮浜嗘晥鐜囷紒
if (instance==null)
銆€銆€ instance 錛?/span> new Singleton();
return instance; 銆€銆€ }
}
鍏朵粬褰㈠紡 :
瀹氫箟涓€涓被錛屽畠鐨勬瀯閫犲嚱鏁頒負 private 鐨勶紝鎵€鏈夋柟娉曚負 static 鐨勩€?/span>
涓€鑸涓虹涓€縐嶅艦寮忚鏇村姞瀹夊叏浜?/span>
絎笁鍗佷笁 Hashtable 鍜?/span> HashMap 錛?/span>
Hashtable 緇ф壙鑷?/span> Dictionary 綾伙紝鑰?/span> HashMap 鏄?/span> Java1.2 寮曡繘鐨?/span> Map interface 鐨勪竴涓疄鐜?/span>
HashMap 鍏佽灝?/span> null 浣滀負涓€涓?/span> entry 鐨?/span> key 鎴栬€?/span> value 錛岃€?/span> Hashtable 涓嶅厑璁?/span>
榪樻湁灝辨槸錛?/span> HashMap 鎶?/span> Hashtable 鐨?/span> contains 鏂規硶鍘繪帀浜嗭紝鏀規垚 containsvalue 鍜?/span> containsK
ey 銆傚洜涓?/span> contains 鏂規硶瀹規槗璁╀漢寮曡搗璇В銆?/span>
鏈€澶х殑涓嶅悓鏄紝 Hashtable 鐨勬柟娉曟槸 Synchronize 鐨勶紝鑰?/span> HashMap 涓嶆槸錛屽湪澶氫釜綰跨▼璁塊棶 Has
htable 鏃訛紝涓嶉渶瑕佽嚜宸變負瀹冪殑鏂規硶瀹炵幇鍚屾錛岃€?/span> HashMap 灝卞繀欏諱負涔嬫彁渚涘鍚屾銆?/span>
Hashtable 鍜?/span> HashMap 閲囩敤鐨?/span>