锘??xml version="1.0" encoding="utf-8" standalone="yes"?> BigDecimal(String)鏄妸涓涓互String琛ㄧず鐨凚igDecimal瀵硅薄鏋勯犱負(fù)BigDecimal瀵硅薄瀹炰緥銆?/p> 涔?fàn)鎯笂锛屽浜帇巩鐐规暟鎴戜滑閮戒細(xì)瀹氫箟湄?fù)double鎴杅loat錛屼絾BigDecimal API鏂囨。涓浜嶣igDecimal(double)鏈夎繖涔堜竴孌佃瘽錛?/p> Note: the results of this constructor can be somewhat unpredictable. One might assume that new BigDecimal(.1) is exactly equal to .1, but it is actually equal to .10000000000000000555111512312578 27021181583404541015625. This is so because .1 cannot be represented exactly as a double (or, for that matter, as a binary fraction of any finite length). Thus, the long value that is being passed in to the constructor is not exactly equal to .1, appearances notwithstanding. The (String) constructor, on the other hand, is perfectly predictable: new BigDecimal(".1") is exactly equal to .1, as one would expect. Therefore, it is generally recommended that the (String) constructor be used in preference to this one 涓嬮潰瀵硅繖孌佃瘽鍋氱畝鍗曡В閲婏細(xì) 娉ㄦ剰錛氳繖涓瀯閫犲櫒鐨勭粨鏋滃彲鑳戒細(xì)鏈変笉鍙鐭ョ殑緇撴灉銆傛湁浜哄彲鑳借鎯?/span>new BigDecimal(.1)絳変簬.1鏄紜殑錛屼絾瀹冨疄闄呬笂鏄瓑浜?/span>.1000000000000000055511151231257827021181583404541015625錛岃繖灝辨槸涓轟粈涔?/span>.1涓嶈兘鐢ㄤ竴涓?/span>double綺劇‘琛ㄧず鐨勫師鍥狅紝鍥犳錛岃繖涓鏀捐繘鏋勯犲櫒涓殑闀垮煎茍涓嶇簿紜殑絳変簬.1錛屽敖綆″瑙傜湅璧鋒潵鏄浉絳夌殑銆?/span> 鐒惰岋紙String錛夋瀯閫犲櫒錛屽垯瀹屽叏鍙鐭ョ殑錛?/span>new BigDecimal(“.1”)濡傚悓鏈熸湜鐨勯偅鏍風(fēng)簿紜殑絳変簬.1錛屽洜姝わ紝錛?/span>String錛夋瀯閫犲櫒鏄浼樺厛鎺ㄨ崘浣跨敤鐨勩?/span> 鐪嬩笅闈㈢殑緇撴灉錛?/p> System.out.println(new BigDecimal(123456789.02).toString()); System.out.println(new BigDecimal("123456789.02").toString()); 杈撳嚭涓猴細(xì) 123456789.01999999582767486572265625 123456789.02 鐜板湪鎴戜滑鐭ラ亾錛屽鏋滈渶瑕佺簿紜綆楋紝闈炶鐢⊿tring鏉ュ閫燘igDecimal涓嶅彲錛?/p>
銆婃繁鍏ava铏氭嫙鏈恒嬩功涓槸榪欐牱鎻忚堪鐨勶細(xì)JVM榪愯鏃舵暟鎹尯鐨勫唴瀛樻ā鍨嬬敱浜旈儴鍒嗙粍鎴愶細(xì)
銆?銆戞柟娉曞尯
銆?銆戝爢
銆?銆慗ava鏍?/span>
銆?銆慞C瀵勫瓨鍣?/span>
銆?銆戞湰鍦版柟娉曟爤
瀵逛簬String s = "hello" ,瀹冪殑铏氭嫙鏈烘寚浠わ細(xì)
瀵逛簬涓婇潰铏氭嫙鏈烘寚浠わ紝鍏跺悇鑷殑鎸囦護(hù)嫻佺▼鍦ㄣ婃繁鍏ava铏氭嫙鏈恒嬭繖鏍鋒弿榪板埌(緇撳悎涓婇潰瀹炰緥)錛?/span>
ldc鎸囦護(hù)鏍煎紡錛歭dc,index
ldc鎸囦護(hù)榪囩▼錛?/span>
瑕佹墽琛宭dc鎸囦護(hù)錛宩vm棣栧厛鏌ユ壘index鎵鎸囧畾鐨勫父閲忔睜鍏ュ彛錛屽湪index鎸囧悜鐨勫父閲忔睜鍏ュ彛錛宩vm灝嗕細(xì)鏌ユ壘constant_integer_info錛宑onstant_float_info鍜宑onstant_string_info鍏ュ彛銆傚鏋滆繕娌℃湁榪欎簺鍏ュ彛錛宩vm浼?xì)瑙f瀽瀹冧滑銆傝屽浜庝笂闈㈢殑hahajvm浼?xì)鎵惧埌constant_string_info鍏ュ彛錛屽悓鏃訛紝灝嗘妸鎸囧悜琚嫎鐣橲tring瀵硅薄錛堢敱瑙f瀽璇ュ叆鍙g殑榪涚▼浜х敓錛夌殑寮曠敤鍘嬪叆鎿嶄綔鏁版爤銆?/span>
astore_1鎸囦護(hù)鏍煎紡錛歛store_1
astore_1鎸囦護(hù)榪囩▼錛?/span>
瑕佹墽琛宎store_1鎸囦護(hù)錛宩vm浠庢搷浣滄暟鏍堥《閮ㄥ脊鍑轟竴涓紩鐢ㄧ被鍨嬫垨鑰卹eturnaddress綾誨瀷鍊鹼紝鐒跺悗灝嗚鍊煎瓨鍏ョ敱绱㈠紩1鎸囧畾鐨勫眬閮ㄥ彉閲忎腑,鍗沖皢寮曠敤綾誨瀷鎴栬卹eturnaddress綾誨瀷鍊煎瓨鍏ュ眬閮ㄥ彉閲?銆?/span>
return 鎸囦護(hù)鐨勮繃紼嬶細(xì)
浠庢柟娉曚腑榪斿洖錛岃繑鍥炲間負(fù)void銆?/span>
璋堜竴涓嬫垜涓漢鐞嗚В錛?/span>
浠庝笂闈㈢殑ldc鎸囦護(hù)鐨勬墽琛岃繃紼嬪彲浠ュ緱鍑猴細(xì)s鐨勫兼槸鏉ヨ嚜琚嫎鐣檚tring瀵硅薄錛堢敱瑙f瀽璇ュ叆鍙g殑榪涚▼浜х敓錛夌殑寮曠敤錛屽嵆鍙互鐞嗚В涓烘槸浠庤鎷樼暀string瀵硅薄鐨勫紩鐢ㄥ鍒惰屾潵鐨勶紝鏁呮垜涓漢鐨勭悊瑙f槸s鐨勫兼槸瀛樺湪鏍堝綋涓備笂闈㈡槸瀵逛簬s鍊煎緱鍒嗘瀽錛屾帴鐫鏄浜?hello"鍊肩殑鍒嗘瀽,鎴戜滑鐭ラ亾錛屽浜巗tring s = "hello" 鍏朵腑"hello"鍊煎湪java紼嬪簭緙栬瘧鏈熷氨紜畾涓嬫潵浜?jiǎn)鐨勩傜畝鍗曚竴鐐硅錛屽氨鏄痟aha鐨勫煎湪紼嬪簭緙栬瘧鎴恈lass鏂囦歡鍚庯紝灝卞湪class鏂囦歡涓敓鎴愪簡(jiǎn)錛堝ぇ瀹跺彲浠ョ敤ue緙栬緫鍣ㄦ垨鍏跺畠鏂囨湰緙栬緫宸ュ叿鍦ㄦ墦寮class鏂囦歡鍚庣殑瀛楄妭鐮佹枃浠朵腑鐪嬪埌榪欎釜hello鍊鹼級(jí)銆傛墽琛宩ava紼嬪簭鐨勮繃紼嬩腑錛岀涓姝ユ槸class鏂囦歡鐢熸垚錛岀劧鍚庤jvm瑁呰澆鍒板唴瀛樻墽琛屻傞偅涔坖vm瑁呰澆榪欎釜class鍒板唴瀛樹腑錛屽叾涓殑hello榪欎釜鍊鹼紝鍦ㄥ唴瀛樹腑鏄庝箞涓哄叾寮杈熺┖闂村茍瀛樺偍鍦ㄥ摢涓尯鍩熶腑鍛紵
璇村埌榪欓噷錛屾垜浠笉濡ㄥ厛鏉ヤ簡(jiǎn)瑙d竴涓媕vm甯擱噺姹犺繖涓粨鏋勶紝銆婃繁鍏ava铏氭嫙鏈恒嬩功涓湁榪欐牱鐨勬弿榪幫細(xì)
甯擱噺姹?/span>
铏氭嫙鏈哄繀欏諱負(fù)姣忎釜琚杞界殑綾誨瀷緇存姢涓涓父閲忔睜銆傚父閲忔睜灝辨槸璇ョ被鍨嬫墍鐢ㄥ埌甯擱噺鐨勪竴涓湁搴忛泦鍜岋紝鍖呮嫭鐩存帴甯擱噺錛坰tring,integer鍜宖loating point甯擱噺錛夊拰瀵瑰叾浠栫被鍨嬶紝瀛楁鍜屾柟娉曠殑絎﹀彿寮曠敤銆傚浜巗tring甯擱噺錛屽畠鐨勫兼槸鍦ㄥ父閲忔睜涓殑銆傝宩vm涓殑甯擱噺姹犲湪鍐呭瓨褰撲腑鏄互琛ㄧ殑褰㈠紡瀛樺湪鐨勶紝瀵逛簬string綾誨瀷錛屾湁涓寮犲浐瀹氶暱搴︾殑constant_string_info琛ㄧ敤鏉ュ瓨鍌ㄦ枃瀛楀瓧絎︿覆鍊鹼紝娉ㄦ剰錛氳琛ㄥ彧瀛樺偍鏂囧瓧瀛楃涓插鹼紝涓嶅瓨鍌ㄧ鍙峰紩鐢ㄣ傝鍒拌繖閲岋紝瀵瑰父閲忔睜涓殑瀛楃涓插肩殑瀛樺偍浣嶇疆搴旇鏈変竴涓瘮杈冩槑浜?jiǎn)鐨勭悊瑙d簡(jiǎn)銆?/span>
鍦ㄤ粙緇嶅畬jvm甯擱噺姹犵殑姒傚康鍚庯紝鎺ョ潃璋堝紑濮嬫彁鍒扮殑"hello"鐨勫肩殑鍐呭瓨鍒嗗竷鐨勪綅緗傚浜巋aha鐨勫鹼紝瀹為檯涓婃槸鍦╟lass鏂囦歡琚玧vm瑁呰澆鍒板唴瀛樺綋涓茍琚紩鎿庡湪瑙f瀽ldc鎸囦護(hù)騫舵墽琛宭dc鎸囦護(hù)涔嬪墠錛宩vm灝卞凡緇忎負(fù)haha榪欎釜瀛楃涓插湪甯擱噺姹犵殑constant_string_info琛ㄤ腑鍒嗛厤浜?jiǎn)绌洪棿鏉ュ瓨鍌╤ello榪欎釜鍊箋傛棦鐒秇ello榪欎釜瀛楃涓插父閲忓瓨鍌ㄥ湪甯擱噺姹犱腑錛屾牴鎹婃繁鍏ava铏氭嫙鏈恒嬩功涓弿榪幫細(xì)甯擱噺姹犳槸灞炰簬綾誨瀷淇℃伅鐨勪竴閮ㄥ垎錛岀被鍨嬩俊鎭篃灝辨槸姣忎竴涓杞澆鐨勭被鍨嬶紝榪欎釜綾誨瀷鍙嶆槧鍒癹vm鍐呭瓨妯″瀷涓槸瀵瑰簲瀛樺湪浜巎vm鍐呭瓨妯″瀷鐨勬柟娉曞尯涓紝涔熷氨鏄繖涓被鍨嬩俊鎭腑鐨勫父閲忔睜姒傚康鏄瓨鍦ㄤ簬鍦ㄦ柟娉曞尯涓紝鑰屾柟娉曞尯鏄湪jvm鍐呭瓨妯″瀷涓殑鍫嗕腑鐢眏vm鏉ュ垎閰嶇殑銆傛墍浠ワ紝hello鐨勫兼槸搴旇鏄瓨鍦ㄥ爢絀洪棿涓殑銆?/span>
鑰屽浜巗tring s = new string("hello") ,瀹冪殑jvm鎸囦護(hù)錛?/span>
瀵逛簬涓婇潰铏氭嫙鏈烘寚浠わ紝鍏跺悇鑷殑鎸囦護(hù)嫻佺▼鍦ㄣ婃繁鍏ava铏氭嫙鏈恒嬭繖鏍鋒弿榪板埌(緇撳悎涓婇潰瀹炰緥)錛?/span>
new鎸囦護(hù)鏍煎紡錛歯ew indexbyte1,indexbyte2
new鎸囦護(hù)榪囩▼錛?/span>
瑕佹墽琛宯ew鎸囦護(hù)錛宩vm閫氳繃璁$畻(indextype1<<8)|indextype2鐢熸垚涓涓寚鍚戝父閲忔睜鐨勬棤絎﹀彿16浣嶇儲(chǔ)寮曘傜劧鍚巎vm鏍規(guī)嵁璁$畻鍑虹殑绱㈠紩鏌ユ壘甯擱噺姹犲叆鍙c傝绱㈠紩鎵鎸囧悜鐨勫父閲忔睜鍏ュ彛蹇呴』涓篶onstant_class_info銆傚鏋滆鍏ュ彛灝氫笉瀛樺湪錛岄偅涔坖vm灝嗚В鏋愯繖涓父閲忔睜鍏ュ彛錛岃鍏ュ彛綾誨瀷蹇呴』鏄被銆俲vm浠庡爢涓負(fù)鏂板璞℃槧鍍忓垎閰嶈凍澶熷ぇ鐨勭┖闂達(dá)紝騫跺皢瀵硅薄鐨勫疄渚嬪彉閲忚涓洪粯璁ゅ箋傛渶鍚巎vm灝嗘寚鍚戞柊瀵硅薄鐨勫紩鐢╫bjectref鍘嬪叆鎿嶄綔鏁版爤銆?/span>
dup鎸囦護(hù)鏍煎紡錛歞up
dup鎸囦護(hù)榪囩▼錛?/span>
瑕佹墽琛宒up鎸囦護(hù)錛宩vm澶嶅埗浜?jiǎn)鎿嶄綔鏁版爤椤堕儴涓涓瓧闀跨殑鍐呭錛岀劧鍚庡啀灝嗗鍒跺唴瀹瑰帇鍏ユ爤銆傛湰鎸囦護(hù)鑳藉浠庢搷浣滄暟鏍堥《閮ㄥ鍒朵換浣曞崟浣嶅瓧闀跨殑鍊箋備絾緇濆涓嶈浣跨敤瀹冩潵澶嶅埗鎿嶄綔鏁版爤欏墮儴浠諱綍涓や釜瀛楅暱(long鍨嬫垨double鍨?涓殑涓涓瓧闀褲備笂闈緥涓紝鍗沖鍒跺紩鐢╫bjectref錛岃繖鏃跺湪鎿嶄綔鏁版爤瀛樺湪2涓紩鐢ㄣ?/span>
ldc鎸囦護(hù)鏍煎紡錛歭dc,index
ldc鎸囦護(hù)榪囩▼錛?/span>
瑕佹墽琛宭dc鎸囦護(hù)錛宩vm棣栧厛鏌ユ壘index鎵鎸囧畾鐨勫父閲忔睜鍏ュ彛錛屽湪index鎸囧悜鐨勫父閲忔睜鍏ュ彛錛宩vm灝嗕細(xì)鏌ユ壘constant_integer_info錛宑onstant_float_info鍜宑onstant_string_info鍏ュ彛銆傚鏋滆繕娌℃湁榪欎簺鍏ュ彛錛宩vm浼?xì)瑙f瀽瀹冧滑銆傝屽浜庝笂闈㈢殑haha,jvm浼?xì)鎵惧埌constant_string_info鍏ュ彛錛屽悓鏃訛紝灝嗘妸鎸囧悜琚嫎鐣檚tring瀵硅薄錛堢敱瑙f瀽璇ュ叆鍙g殑榪涚▼浜х敓錛夌殑寮曠敤鍘嬪叆鎿嶄綔鏁版爤銆?/span>
invokespecial鎸囦護(hù)鏍煎紡錛歩nvokespecial,indextype1,indextype2
invokespecial鎸囦護(hù)榪囩▼錛氬浜庤綾昏岃█錛岃鎸囦護(hù)鏄敤鏉ヨ繘琛屽疄渚嬪垵濮嬪寲鏂規(guī)硶鐨勮皟鐢ㄣ傞壌浜庤鎸囦護(hù)綃囧箙錛屽叿浣撳彲浠ユ煡闃呫婃繁鍏ava铏氭嫙鏈恒嬩腑鎻忚堪銆備笂闈緥瀛愪腑錛屽嵆閫氳繃鍏朵腑涓涓紩鐢ㄨ皟鐢╯tring綾葷殑鏋勯犲櫒錛屽垵濮嬪寲瀵硅薄瀹炰緥錛岃鍙︿竴涓浉鍚岀殑寮曠敤鎸囧悜榪欎釜琚垵濮嬪寲鐨勫璞″疄渚嬶紝鐒跺悗鍓嶄竴涓紩鐢ㄥ脊鍑烘搷浣滄暟鏍堛?/span>
astore_1鎸囦護(hù)鏍煎紡錛歛store_1
astore_1鎸囦護(hù)榪囩▼錛?/span>
瑕佹墽琛宎store_1鎸囦護(hù)錛宩vm浠庢搷浣滄暟鏍堥《閮ㄥ脊鍑轟竴涓紩鐢ㄧ被鍨嬫垨鑰卹eturnaddress綾誨瀷鍊鹼紝鐒跺悗灝嗚鍊煎瓨鍏ョ敱绱㈠紩1鎸囧畾鐨勫眬閮ㄥ彉閲忎腑,鍗沖皢寮曠敤綾誨瀷鎴栬卹eturnaddress綾誨瀷鍊煎瓨鍏ュ眬閮ㄥ彉閲?銆?/span>
return 鎸囦護(hù)鐨勮繃紼?
浠庢柟娉曚腑榪斿洖錛岃繑鍥炲間負(fù)void銆?/span>
瑕佹墽琛宎store_1鎸囦護(hù)錛宩vm浠庢搷浣滄暟鏍堥《閮ㄥ脊鍑轟竴涓紩鐢ㄧ被鍨嬫垨鑰卹eturnaddress綾誨瀷鍊鹼紝鐒跺悗灝嗚鍊煎瓨鍏ョ敱绱㈠紩1鎸囧畾鐨勫眬閮ㄥ彉閲忎腑,鍗沖皢寮曠敤綾誨瀷鎴栬卹eturnaddress綾誨瀷鍊煎瓨鍏ュ眬閮ㄥ彉閲?銆?/span>
閫氳繃涓婇潰6涓寚浠わ紝鍙互鐪嬪嚭錛宻tring s = new string("hello");涓殑hello瀛樺偍鍦ㄥ爢絀洪棿涓紝鑰宻鍒欐槸鍦ㄦ搷浣滄暟鏍堜腑銆?/span>
涓婇潰鏄s鍜宧aha鍊肩殑鍐呭瓨鎯呭喌鐨勫垎鏋愬拰鐞嗚В錛涢偅瀵逛簬string s = new string("hello");璇彞,鍒板簳鍒涘緩浜?jiǎn)鍑犱釜瀵硅薄鍛?
鎴戠殑鐞嗚В錛氳繖閲?hello"鏈韓灝辨槸甯擱噺姹犱腑鐨勪竴涓璞★紝鑰屽湪榪愯鏃舵墽琛宯ew string()鏃訛紝灝嗗父閲忔睜涓殑瀵硅薄澶嶅埗涓浠芥斁鍒板爢涓紝騫朵笖鎶婂爢涓殑榪欎釜瀵硅薄鐨勫紩鐢ㄤ氦緇檚鎸佹湁銆傛墍浠ヨ繖鏉¤鍙ュ氨鍒涘緩浜?涓猻tring瀵硅薄銆?/span>
涓嬮潰鏄竴浜泂tring鐩稿叧鐨勫父瑙侀棶棰橈細(xì)
String涓殑final鐢ㄦ硶鍜岀悊瑙?/span>
final stringbuffer a = new stringbuffer("111");
final stringbuffer b = new stringbuffer("222");
a=b;//姝ゅ彞緙栬瘧涓嶉氳繃
final stringbuffer a = new stringbuffer("111");
a.append("222");//緙栬瘧閫氳繃
鍙錛宖inal鍙寮曠敤鐨?鍊?(鍗沖唴瀛樺湴鍧)鏈夋晥錛屽畠榪嬌寮曠敤鍙兘鎸囧悜鍒濆鎸囧悜鐨勯偅涓璞★紝鏀瑰彉瀹冪殑鎸囧悜浼?xì)瀵艰嚧缂栬瘧鏈熼敊璇傝嚦浜庡畠鎵鎸囧悜鐨勫璞$殑鍙樺寲錛宖inal鏄笉璐熻矗鐨勩?/span>
String 甯擱噺姹犻棶棰樼殑鍑犱釜渚嬪瓙
涓嬮潰鏄嚑涓父瑙佷緥瀛愮殑姣旇緝鍒嗘瀽鍜岀悊瑙o細(xì)
銆?銆?/span>
鍒嗘瀽錛歫vm瀵逛簬瀛楃涓插父閲忕殑"+"鍙瘋繛鎺ワ紝灝嗙▼搴忕紪璇戞湡錛宩vm灝卞皢甯擱噺瀛楃涓茬殑"+"榪炴帴浼樺寲涓鴻繛鎺ュ悗鐨勫鹼紝鎷?a" + 1鏉ヨ錛岀粡緙栬瘧鍣ㄤ紭鍖栧悗鍦╟lass涓氨宸茬粡鏄痑1銆傚湪緙栬瘧鏈熷叾瀛楃涓插父閲忕殑鍊煎氨紜畾涓嬫潵錛屾晠涓婇潰紼嬪簭鏈緇堢殑緇撴灉閮戒負(fù)true銆?/span>
銆?銆?/span>
鍒嗘瀽錛歫vm瀵逛簬瀛楃涓插紩鐢紝鐢變簬鍦ㄥ瓧絎︿覆鐨?+"榪炴帴涓紝鏈夊瓧絎︿覆寮曠敤瀛樺湪錛岃屽紩鐢ㄧ殑鍊煎湪紼嬪簭緙栬瘧鏈熸槸鏃犳硶紜畾鐨勶紝鍗?a" + bb鏃犳硶琚紪璇戝櫒浼樺寲錛屽彧鏈夊湪紼嬪簭榪愯鏈熸潵鍔ㄦ佸垎閰嶅茍灝嗚繛鎺ュ悗鐨勬柊鍦板潃璧嬬粰b銆傛墍浠ヤ笂闈㈢▼搴忕殑緇撴灉涔熷氨涓篺alse銆?/span>
銆?銆?/span>
鍒嗘瀽錛氬拰[3]涓敮涓涓嶅悓鐨勬槸bb瀛楃涓插姞浜?jiǎn)final淇グ錛屽浜巉inal淇グ鐨勫彉閲忥紝瀹冨湪緙栬瘧鏃惰瑙f瀽涓哄父閲忓肩殑涓涓湰鍦版嫹璐濆瓨鍌ㄥ埌鑷繁鐨勫父閲忔睜涓垨宓屽叆鍒板畠鐨勫瓧鑺傜爜嫻佷腑銆傛墍浠ユ鏃剁殑"a" + bb鍜?a" + "b"鏁堟灉鏄竴鏍風(fēng)殑銆傛晠涓婇潰紼嬪簭鐨勭粨鏋滀負(fù)true銆?/span>
銆?銆?/span>
鍒嗘瀽錛歫vm瀵逛簬瀛楃涓插紩鐢╞b錛屽畠鐨勫煎湪緙栬瘧鏈熸棤娉曠‘瀹氾紝鍙湁鍦ㄧ▼搴忚繍琛屾湡璋冪敤鏂規(guī)硶鍚庯紝灝嗘柟娉曠殑榪斿洖鍊煎拰"a"鏉ュ姩鎬佽繛鎺ュ茍鍒嗛厤鍦板潃涓篵錛屾晠涓婇潰紼嬪簭鐨勭粨鏋滀負(fù)false銆?/span>
閫氳繃涓婇潰4涓緥瀛愬彲浠ュ緱鍑哄緱鐭ワ細(xì)
string s = "a" + "b" + "c";
灝辯瓑浠蜂簬string s = "abc";
string a = "a";
string b = "b";
string c = "c";
string s = a + b + c;
榪欎釜灝變笉涓鏍蜂簡(jiǎn)錛屾渶緇堢粨鏋滅瓑浜庯細(xì)
stringbuffer temp = new stringbuffer();
temp.append(a).append(b).append(c);
string s = temp.tostring();
鐢變笂闈㈢殑鍒嗘瀽緇撴灉錛屽彲灝變笉闅炬帹鏂嚭string 閲囩敤榪炴帴榪愮畻絎︼紙+錛夋晥鐜囦綆涓嬪師鍥犲垎鏋愶紝褰㈠榪欐牱鐨勪唬鐮侊細(xì)
姣忓仛涓嬈?+ 灝變駭鐢熶釜stringbuilder瀵硅薄錛岀劧鍚巃ppend鍚庡氨鎵旀帀銆備笅嬈″驚鐜啀鍒拌揪鏃墮噸鏂頒駭鐢熶釜stringbuilder瀵硅薄錛岀劧鍚?append 瀛楃涓詫紝濡傛寰幆鐩磋嚦緇撴潫銆?濡傛灉鎴戜滑鐩存帴閲囩敤 stringbuilder 瀵硅薄榪涜 append 鐨勮瘽錛屾垜浠彲浠ヨ妭鐪?n - 1 嬈″垱寤哄拰閿姣佸璞$殑鏃墮棿銆傛墍浠ュ浜庡湪寰幆涓榪涜瀛楃涓茶繛鎺ョ殑搴旂敤錛屼竴鑸兘鏄敤stringbuffer鎴杝tringbulider瀵硅薄鏉ヨ繘琛宎ppend鎿嶄綔銆?/span>
string瀵硅薄鐨刬ntern鏂規(guī)硶鐞嗚В鍜屽垎鏋愶細(xì)
榪欓噷鐢ㄥ埌java閲岄潰鏄竴涓父閲忔睜鐨勯棶棰樸傚浜巗1+s2鎿嶄綔錛屽叾瀹炴槸鍦ㄥ爢閲岄潰閲嶆柊鍒涘緩浜?jiǎn)涓涓柊鐨勫璞?s淇濆瓨鐨勬槸榪欎釜鏂板璞″湪鍫嗙┖闂寸殑鐨勫唴瀹癸紝鎵浠涓巃鐨勫兼槸涓嶇浉絳夌殑銆傝屽綋璋冪敤s.intern()鏂規(guī)硶錛屽嵈鍙互榪斿洖s鍦ㄥ父閲忔睜涓殑鍦板潃鍊鹼紝鍥犱負(fù)a鐨勫煎瓨鍌ㄥ湪甯擱噺姹犱腑錛屾晠s.intern鍜宎鐨勫肩浉絳夈?br />
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鍙岀簿搴︽誕鐐規(guī)暟錛歞ouble--64浣嶏紙8瀛楄妭錛?-鏈夋晥鏁板瓧16浣嶏紱
瓚呰繃double琛ㄧず鑼冨洿鐨勶紝涓寰嬬敤BigDecimal銆?br />鍏充簬BigDecimal鐨勬瀯閫狅紝闇瑕佷粠String鏋勯狅紝鍒囪涓嶅彲鐢眃ouble鏋勯?br /> 鍗充笉鍙敤 new BigDecimal(double var) [X]
鑰屾槸閫氳繃 new BigDecimal(String var)
鍘熷洜鍙傝?a >http://hi.baidu.com/waiting__for__you/blog/item/967206ec863751d3b21cb170.html
銆?br /> BigDecimal(double)鏄妸涓涓猟ouble綾誨瀷鍗佽繘鍒舵暟鏋勯犱負(fù)涓涓狟igDecimal瀵硅薄瀹炰緥銆?/span>
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鐜板湪璁よ瘑鍒版劅鎯呰繖鐜╂剰鍎跨殑濞佸姏浜?jiǎn)鍚уQ?/p>
鏄庣煡鑷繁娌¤祫鏈紝娌¤兘鍔涳紝涓轟綍榪樿鐜╄繖鏈潵鐜╀笉璧風(fēng)殑娓告垙錛?/p>
鐜板湪鍌?cè)潨间簡(jiǎn)锛熶綘鍧愮殑浣忎箞锛熶綘鎯崇殑寮涔堬紵浣犺繕鏈夎兘鍔涚戶緇綘鐨勫ぇ瀛︾悊鎯充箞錛?/p>
浣犺繕鏄斁涓嶄笅錛屼綘鎬ヨ簛錛屼綘鏃犳墍閫備粠錛屼綘瓚婃槸鎬ュ垏瓚婃槸琛ㄧ幇寰楁病搴曟皵錛屾病鎬濊礬
浣犻搴熷闀挎椂闂翠簡(jiǎn)錛熶綘榪樻兂楗垮嚑欏塊キ錛熶綘榪樿嚜嬈烘浜虹殑騫繪兂鍒頒粈涔堟椂鍊欙紵浣犱粬濡堟椿寰楄繕鏄釜浜烘牱涔堬紵
榪欐湁浠涔堝彈涓嶄簡(jiǎn)鐨勶紵澶氬ぇ鐨勫帇鍔涗綘娌℃壙鍙楄繃錛?/p>
涓涓コ鐢熺殑鐤忕灝辨妸浣犲嚮鍨垚榪欐牱瀛愪簡(jiǎn)錛?/p>
浣犺繕璁や負(fù)鑷繁紼抽噸錛熻繕璁や負(fù)鑷繁澶勪簨鍐烽潤錛熻繕璁や負(fù)鑷繁鑳介潰瀵瑰満闈笉鎬ヤ笉鎱岃嚜淇″簲瀵瑰悧錛?/p>
鎰熸儏榪欑偣鐮翠簨鍎夸竴鏉ワ紝浣犺嚜淇¤窇鍝幓浜?jiǎn)锛熷喎闈欒窇鍝効鍘讳簡(jiǎn)锛?/p>
浣犲帇鏍瑰氨涓嶆槸璋堟亱鐖辯殑縐嶏紒
浣犺浣犳病緇忛獙錛屾病緇忛獙浣犺窇鏉ヨ皥浠涔堣皥錛熶綘鍐插姩錛?/p>
浣犲掓尯瀹炲湪鐨勬姇鍏ヨ繘鏉ヤ簡(jiǎn)錛屼漢瀹跺彈浼ら浜?jiǎn)浣犵幇鍦ㄥ拫鍔炲Q熷偦浜?jiǎn)鍚уQ熻糠鎯樹簡(jiǎn)鍚э紵榪橀鐨勫洖鍘諱箞錛?/p>
涓嶈寰楃獫鍥婁箞錛?/p>
鏇劇粡鐨勪綘鏄繖鏍峰瓙涔堬紵
浣犱笉鏄繚鎸侀珮鍌茬潃涔堬紵浣犱笉鏄湅涓嶆儻鏌愪簺浜哄枾鍤f誕韜佺殑鐢熸椿錛岀湅涓嶆儻鏌愪簺浜虹埍鐪嬬儹闂圭埍媧誨湪鍒漢鐨勪笘鐣岄噷涔堬紵
浣犱笉鏄啩鎲潃涓浠藉厖婊¢粯濂戙佸厖婊$悊瑙c佸郊姝ら紦鍔辯殑鐖辨儏涔堬紵
浣犱笉鏄渶涓嶆兂璁╁埆浜烘妸鑷繁褰撳皬涓戠湅浜?jiǎn)涔堝Q?/p>
浣犱笉鏄渶鐪嬩笉鎯竴涓敺浜烘妸鍢村反娑傜殑鐢滅敎鐨勫幓鍗氬彇瀣夌瑧涔堬紵
浣犱笉鏄渶鐪嬩笉璧蜂竴涓敺浜烘病鐪熸潗瀹炴枡錛岀敤璦絎戞帺楗扮┖铏氱殑涔堬紵
鑰屼綘鐜板湪鍙堝湪鍋氫粈涔堝憿錛?/p>
浣犲皾璇曠潃瀛︿細(xì)榪欎簺錛屽洜涓轟綘鍙戠幇娌¤繖浜涗笢瑗夸綘鏃犳硶鍦ㄦ劅鎯呰繖涓笘鐣岄噷鑾峰緱鎹峰緞
綆椾簡(jiǎn)鍚э紝浣犲仛涓嶅嚭鏉ワ紝浣犲潥鎸佷笉涓嬫潵
浣犲ぉ鐪熺殑璁や負(fù)褰兼閮戒細(xì)鑷劧鑰岀劧鐨勭悊瑙e茍璧板埌涓璧鳳紵錛?/p>
浣嗘槸濂逛竴瀹氭劅鍙楃殑鍒頒箞錛熷ス涓瀹氳兘欏朵綇榪欎喚鍘嬪姏錛屽繊鑰愪綘鐨勮妭濂忎箞錛燂紵
浣犺繖涓偦瀛愶紝璋侀兘涓嶆槸浣犳兂璞′腑鐨勯偅涔堜竴鑷達(dá)紵璋侀兘涓嶈兘鎶椾綇澶鎰熸儏甯︽潵鐨勫帇鍔涳紵
浣犳妸涓鍒囬兘鎯崇殑閭d箞鑷劧錛屼竴鍒囬兘鎯寵薄鐨勯偅涔堢編濂斤紝鍒板ご鏉ワ紝鎶婃墍鏈変漢閮藉浜?/p>
浣犳湁浜涜嚜縐佷簡(jiǎn)
浣犵己涔忕敺瀛愭眽鐨勬皵姒?/p>
鎰熸儏涔熶竴鏍鳳紝鎷跨殑璧鋒潵錛屼篃寰楁斁鐨勪笅
瑙夊緱鏀句笉涓嬶紝灝卞簲璇ユ兂鍔炴硶鎸藉洖
涓鍛沖効鐨勮嚜鎴戝弽鐪佸拰綰犵粨錛屾湁浠涔堢敤錛?/p>
鎰熸儏瑕佸己鍔?/p>
鎰熸儏闇瑕佹壙鎷呰矗浠?/p>
鎰熸儏涓嶈兘鍙緷闈犲績鐞嗭紝璇ユ湁浠樺嚭鏈変粯鍑猴紝璇ユ湁琛屽姩鏈夎鍔?/p>
浣犳槑鐧藉悧錛?/p>
浣犱笉璇ヨ繃鍒嗙殑鑷矗錛岀粰鍫曡惤鎵懼熷彛
浣犱笉鏄病鏈変富鍔ㄨ繃
浣犱笉鏄病鍒涢犺繃鏈轟細(xì)
鍝曚綘浠兘鎴愬姛涓嬈★紵
浣犱滑鐨勫績?yōu)兗?xì)褰誨簳鏀懼紑
闅忕紭錛熼殢緙樺惂錛岀浉淇$紭鍒嗗ぉ娉ㄥ畾錛岃皝璁╀綘浠笉鑳藉湪涓璧?/p>
涔熻浜哄涓嶈垗寰椾負(fù)浣犵壓鐗查偅涔堝
涔熻浜哄鏍規(guī)湰灝變笉鍠滄浣?/p>
涔熻
浜哄鐪熺殑鏈夊師鍥?/p>
浣犱負(fù)浣曞氨涓嶈兘鐥涘揩涓鐐癸紵緇欒嚜宸變竴涓槑紜殑絳斿
涓嬪喅蹇冨鑷繁鐙犱竴鐐癸紝瀵瑰埆浜虹嫚涓鐐?/p>
浣犳槸涓敺浜?/p>
涓嶅ソ浣庝笅澶村悜鍒漢鍊捐瘔
閭e氨鐥涘揩鐨勫捊涓嬪幓
鑳戒簤鍙栧氨灝藉姏浜夊彇錛岀粰鑷繁涓涓悊鐢憋紝緇欏郊姝や竴涓氦浠?/p>
浣犱笉鑳界潃鎬?/p>
浣犲緱鍐烽潤錛岀湡鐨勮鍐烽潤
榪欎笉鏄綘鐢熸椿鐨勫叏閮紝瀹冧笉鑳藉崰浣犲叏閮ㄧ殑鏃墮棿
灝介噺涓嶅幓澶氭兂
緇欏ス涓孌墊椂闂?/p>
璁╁ス緙撳啿錛岃濂瑰績闈?/p>
浣犺寰楀儚涓皬涓戜竴鏍峰幓鎵撴壈濂癸紝鏄ス甯屾湜鐪嬪埌鐨勪箞錛?/p>
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涓嶈鏈緇堢粨鏋滃浣?/p>
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緇х畫錛屼綘瑕佹洿鍔犵弽鎯?/p>
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鐢蜂漢錛屾渶鍚庤緇欒嚜宸變竴涓竻鏅扮殑浜や唬
榪欏彨鐖卞悧錛?/p>
搴旇綆楁槸浜?jiǎn)鍚?/p>
浣犲湪鐖辯潃濂?/p>
涓嶇濂規(guī)庝箞鎯?/p>
褰撲綔濂瑰彧鏄竴鏃剁殑鎾掑▏鐢熸皵鍚?/p>
絳夊ス
鍐烽潤鐨勭瓑濂?/p>
濡傛灉鎺ュ彈錛屾斁寮浣犵殑鍏ㄩ儴錛屽儚涓敺浜虹殑鏍鳳紝緇欏ス騫哥
濡傛灉紱誨紑錛屽仛鍒板郊姝ょ殑鍧﹁瘹錛岀紱忓ス
涓嶇鎬庢牱
榪欎簺澶╄瀵硅嚜宸辮嚜縐侊紒
濂藉ソ闈㈠鐢熸椿
涓嶈兘娑堟瀬鍫曡惤
鍗冧竾涓嶈兘錛?br />
-------->鎴戜笉鍘繪兂鑳藉惁璧㈠緱鐖辨儏
鏃㈢劧閽熸儏浜庣帿鐟?br />
灝卞媷鏁㈠湴鍚愰湶鐪熻瘹
鎴戜笉鍘繪兂韜悗浼?xì)涓嶄細(xì)琚潵瀵掗鍐烽?br />
鏃㈢劧鐩爣鏄湴騫崇嚎
鐣欑粰涓栫晫鐨勫彧鑳芥槸鑳屽獎(jiǎng)
鎴戜笉鍘繪兂鏈潵鏄鉤鍧﹁繕鏄償娉?br />
鍙鐑埍鐢熷懡
涓鍒囷紝閮藉湪鎰忔枡涔嬩腑