Java涓爢鍜屾爤鐨勫尯鍒?一)

Java涓爢鍜屾爤鐨勫尯鍒?1)

鍫嗗拰鏍堢殑鍖哄埆

鏍堜笌鍫嗛兘鏄疛ava鐢ㄦ潵鍦≧am涓瓨鏀炬暟鎹殑鍦版柟銆備笌C++涓嶅悓锛孞ava鑷姩绠＄悊鏍堝拰鍫嗭紝绋嬪簭鍛樹笉鑳界洿鎺ュ湴璁剧疆鏍堟垨鍫嗐€?

Java 鐨勫爢鏄竴涓繍琛屾椂鏁版嵁鍖?绫荤殑(瀵硅薄浠庝腑鍒嗛厤绌洪棿銆傝繖浜涘璞￠€氳繃new銆乶ewarray銆乤newarray鍜宮ultianewarray绛夋寚浠ゅ缓绔嬶紝瀹冧滑涓嶉渶瑕佺▼搴忎唬鐮佹潵鏄惧紡鐨勯噴鏀俱€傚爢鏄敱鍨冨溇鍥炴敹鏉ヨ礋璐ｇ殑锛屽爢鐨勪紭鍔挎槸鍙互鍔ㄦ€佸湴鍒嗛厤鍐呭瓨澶у皬锛岀敓瀛樻湡涔熶笉蹇呬簨鍏堝憡璇夌紪璇戝櫒锛屽洜涓哄畠鏄湪杩愯鏃跺姩鎬佸垎閰嶅唴瀛樼殑锛孞ava鐨勫瀮鍦炬敹闆嗗櫒浼氳嚜鍔ㄦ敹璧拌繖浜涗笉鍐嶄娇鐢ㄧ殑鏁版嵁銆備絾缂虹偣鏄紝鐢变簬瑕佸湪杩愯鏃跺姩鎬佸垎閰嶅唴瀛橈紝瀛樺彇閫熷害杈冩參銆?

鏍堢殑浼樺娍鏄紝瀛樺彇閫熷害姣斿爢瑕佸揩锛屼粎娆′簬瀵勫瓨鍣紝鏍堟暟鎹彲浠ュ叡浜€備絾缂虹偣鏄紝瀛樺湪鏍堜腑鐨勬暟鎹ぇ灏忎笌鐢熷瓨鏈熷繀椤绘槸纭畾鐨勶紝缂轰箯鐏垫椿鎬с€傛爤涓富瑕佸瓨鏀句竴浜涘熀鏈被鍨嬬殑鍙橀噺锛? int, short, long, byte, float, double, boolean, char锛夊拰瀵硅薄鍙ユ焺銆?

鏍堟湁涓€涓緢閲嶈鐨勭壒娈婃€э紝灏辨槸瀛樺湪鏍堜腑鐨勬暟鎹彲浠ュ叡浜€傚亣璁炬垜浠悓鏃跺畾涔夛細
int a = 3;
int b = 3锛?
缂栬瘧鍣ㄥ厛澶勭悊int a = 3锛涢鍏堝畠浼氬湪鏍堜腑鍒涘缓涓€涓彉閲忎负a鐨勫紩鐢紝鐒跺悗鏌ユ壘鏍堜腑鏄惁鏈?杩欎釜鍊硷紝濡傛灉娌℃壘鍒帮紝灏卞皢3瀛樻斁杩涙潵锛岀劧鍚庡皢a鎸囧悜3銆傛帴鐫€澶勭悊int b = 3锛涘湪鍒涘缓瀹宐鐨勫紩鐢ㄥ彉閲忓悗锛屽洜涓哄湪鏍堜腑宸茬粡鏈?杩欎釜鍊硷紝渚垮皢b鐩存帴鎸囧悜3銆傝繖鏍凤紝灏卞嚭鐜颁簡a涓巄鍚屾椂鍧囨寚鍚?鐨勬儏鍐点€?

杩欐椂锛屽鏋滃啀浠=4锛涢偅涔堢紪璇戝櫒浼氶噸鏂版悳绱㈡爤涓槸鍚︽湁4鍊硷紝濡傛灉娌℃湁锛屽垯灏?瀛樻斁杩涙潵锛屽苟浠鎸囧悜4锛涘鏋滃凡缁忔湁浜嗭紝鍒欑洿鎺ュ皢a鎸囧悜杩欎釜鍦板潃銆傚洜姝鍊肩殑鏀瑰彉涓嶄細褰卞搷鍒癰鐨勫€笺€?

瑕佹敞鎰忚繖绉嶆暟鎹殑鍏变韩涓庝袱涓璞＄殑寮曠敤鍚屾椂鎸囧悜涓€涓璞＄殑杩欑鍏变韩鏄笉鍚岀殑锛屽洜涓鸿繖绉嶆儏鍐礱鐨勪慨鏀瑰苟涓嶄細褰卞搷鍒癰, 瀹冩槸鐢辩紪璇戝櫒瀹屾垚鐨勶紝瀹冩湁鍒╀簬鑺傜渷绌洪棿銆傝€屼竴涓璞″紩鐢ㄥ彉閲忎慨鏀逛簡杩欎釜瀵硅薄鐨勫唴閮ㄧ姸鎬侊紝浼氬奖鍝嶅埌鍙︿竴涓璞″紩鐢ㄥ彉閲忋€?

String鏄竴涓壒娈婄殑鍖呰绫绘暟鎹€傚彲浠ョ敤锛?
String str = new String("abc");
String str = "abc";
涓ょ鐨勫舰寮忔潵鍒涘缓锛岀涓€绉嶆槸鐢╪ew()鏉ユ柊寤哄璞＄殑锛屽畠浼氬湪瀛樻斁浜庡爢涓€傛瘡璋冪敤涓€娆″氨浼氬垱寤轰竴涓柊鐨勫璞°€?
鑰岀浜岀鏄厛鍦ㄦ爤涓垱寤轰竴涓String绫荤殑瀵硅薄寮曠敤鍙橀噺str锛岀劧鍚庢煡鎵炬爤涓湁娌℃湁瀛樻斁"abc"锛屽鏋滄病鏈夛紝鍒欏皢"abc"瀛樻斁杩涙爤锛屽苟浠tr鎸囧悜鈥漚bc鈥濓紝濡傛灉宸茬粡鏈夆€漚bc鈥?鍒欑洿鎺ヤ护str鎸囧悜鈥渁bc鈥濄€?

姣旇緝绫婚噷闈㈢殑鏁板€兼槸鍚︾浉绛夋椂锛岀敤equals()鏂规硶锛涘綋娴嬭瘯涓や釜鍖呰绫荤殑寮曠敤鏄惁鎸囧悜鍚屼竴涓璞℃椂锛岀敤==锛屼笅闈㈢敤渚嬪瓙璇存槑涓婇潰鐨勭悊璁恒€?
String str1 = "abc";
String str2 = "abc";
System.out.println(str1==str2); //true
鍙互鐪嬪嚭str1鍜宻tr2鏄寚鍚戝悓涓€涓璞＄殑銆?

String str1 =new String ("abc");
String str2 =new String ("abc");
System.out.println(str1==str2); // false
鐢╪ew鐨勬柟寮忔槸鐢熸垚涓嶅悓鐨勫璞°€傛瘡涓€娆＄敓鎴愪竴涓€?


鍥犳鐢ㄧ浜岀鏂瑰紡鍒涘缓澶氫釜鈥漚bc鈥濆瓧绗︿覆,鍦ㄥ唴瀛樹腑鍏跺疄鍙瓨鍦ㄤ竴涓璞¤€屽凡. 杩欑鍐欐硶鏈夊埄涓庤妭鐪佸唴瀛樼┖闂? 鍚屾椂瀹冨彲浠ュ湪涓€瀹氱▼搴︿笂鎻愰珮绋嬪簭鐨勮繍琛岄€熷害锛屽洜涓篔VM浼氳嚜鍔ㄦ牴鎹爤涓暟鎹殑瀹為檯鎯呭喌鏉ュ喅瀹氭槸鍚︽湁蹇呰鍒涘缓鏂板璞°€傝€屽浜嶴tring str = new String("abc")锛涚殑浠ｇ爜锛屽垯涓€姒傚湪鍫嗕腑鍒涘缓鏂板璞★紝鑰屼笉绠″叾瀛楃涓插€兼槸鍚︾浉绛夛紝鏄惁鏈夊繀瑕佸垱寤烘柊瀵硅薄锛屼粠鑰屽姞閲嶄簡绋嬪簭鐨勮礋鎷呫€?

鍙︿竴鏂归潰, 瑕佹敞鎰? 鎴戜滑鍦ㄤ娇鐢ㄨ濡係tring str = "abc"锛涚殑鏍煎紡瀹氫箟绫绘椂锛屾€绘槸鎯冲綋鐒跺湴璁や负锛屽垱寤轰簡String绫荤殑瀵硅薄str銆傛媴蹇冮櫡闃憋紒瀵硅薄鍙兘骞舵病鏈夎鍒涘缓锛佽€屽彲鑳藉彧鏄寚鍚戜竴涓厛鍓嶅凡缁忓垱寤虹殑瀵硅薄銆傚彧鏈夐€氳繃new()鏂规硶鎵嶈兘淇濊瘉姣忔閮藉垱寤轰竴涓柊鐨勫璞°€?
鐢变簬String绫荤殑immutable鎬ц川锛屽綋String鍙橀噺闇€瑕佺粡甯稿彉鎹㈠叾鍊兼椂锛屽簲璇ヨ€冭檻浣跨敤StringBuffer绫伙紝浠ユ彁楂樼▼搴忔晥鐜囥€?

鏍堜腑涓昏瀛樻斁涓€浜涘熀鏈被鍨嬬殑鍙橀噺锛? int, short, long, byte, float, double, boolean, char锛夊拰瀵硅薄鍙ユ焺銆?

鍏充簬Java鏍堜笌鍫嗙殑鎬濊€?
http://www.duduwolf.com/post/3.asp