Java 基础核心总结-【千锋教育】程序设计基础学习笔记

Java चᏐ໐ஞ௛ᕮ Java चᏐ໐ஞ௛ᕮ Java ༷ᬿ Ջԍฎ JavaҘ Java ጱᇙᅩ Java ୏ݎሾह JDK JRE Java ୏ݎሾहᯈᗝ Java च๜᧍ဩ හഝᔄࣳ चᏐ᧍ဩ ᬩᓒᒧ Java ಗᤈഴၞګᑕ ๵կ᧍ݙ if ๵կ᧍ݙ if...else ๵կ᧍ݙ if...else if ग़ړඪ᧍ݙ switch ग़ړඪ᧍ݙ ஗ሾ᧍ݙ while ஗ሾ᧍ݙ do...while ஗ሾ for ஗ሾ᧍ݙ ᪡᫨᧍ݙ break ᧍ݙ continue ᧍ݙ ᶎݻ੒᨝ ᔄԞฎӞᐿ੒᨝ ੒᨝ጱڠୌ ં௔޾ොဩ ຅᭜ොဩ ොဩ᯿᫹ ොဩጱ᯿ٟ ত۸ڡ ᔄጱڡত۸ ౮ާڡত۸ ຅᭜ڡ࢏ত۸ ত۸ᶲଧڡ හᕟڡত۸ ੒᨝ጱᲀྪ ੒᨝֢አऒ this ޾ super ᦢᳯഴګ๦ᴴ ᖀಥ ग़ா ᕟݳ դቘ Ӥ᫨ࣳݻ static final ള޾ݗು᨝ᔄ ളݗ ು᨝ᔄ ୑ଉ ᦊᦩ Exception Ջԍฎ Throwable ଉᥠጱ Exception Ө Exception ํىጱ Java ىᲫਁ throws ޾ throw try ̵finally ̵catch Ջԍฎ Error ٖ᮱ᔄ ୌٖ᮱ᔄڠ ᵞݳ Iterable ളݗ ᶮ੶ളݗ ArrayList Vector LinkedList ᔄ Stack HashSet TreeSet LinkedHashSet ᔄ PriorityQueue HashMap TreeMap ᔄ LinkedHashMap ᔄ Hashtable ᔄ IdentityHashMap ᔄ WeakHashMap ᔄ Collections ᔄ ᵞݳਫሿᔄᇙ஄ࢶ ာ୵ ာࣳጱֵአ አာࣳᤒᐏᔄ አာࣳᤒᐏളݗ ာࣳොဩ ာࣳ᭗ᯈᒧ ੘ݍ Class ᔄ Field ᔄ Method ᔄ ClassLoader ᔄ ຍԈ ຍԈᇙ௔ ຍԈ޾ฦ᭗ᔄӞ໏ ຍԈᐟᑃԏ॒ ຍԈᔄ I/O File ᔄ चᏐ IO ᔄ޾ፘىොဩ InputStream OutputStream Reader ᔄ Writer ᔄ InputStream ٌ݊ৼᔄ OutputStream ٌ݊ৼᔄ Reader ٌ݊ৼᔄ Writer ٌ݊ৼᔄ ဳᥴ ᐿ॒ቘොୗپԭ null ጱى य़ੜٟභఽ null ฎձ֜୚አᔄࣳጱڡত꧊ null ݝฎӞᐿᇙྛጱ꧊ ֵአ Null-Safe ොဩ null ڣෙ ࢶԭ௏ᖌ੕ى Java.IO Java.lang Java.math Java.net ᕰӥᶎᬯԶٖ਻ᬰᤈᦖᥴ̶ٖ਻உଗ҅ੜվ֎ժ፡ਠᬮ૶๕ࢱ౯տ҅މࢶ๶፡Ӟӥ๜ᓤ෈ᒍጱ௏ᖌ੕ض ӧނ᫨̶ݎ ӥᶎ୏ত౯ժጱ෈ᒍ̶ Java ༷ᬿ Ջԍฎ JavaҘ Java ฎ Sun Microsystems ԭ1995 ଙḒེݎ૲ጱӞᐿ ᖫᑕ᧍᥺ ᖫᑕ᧍᥺ᬮྲ᫾অቘ̶ݣᦇᓒଘ޾ ᥴ҅ᮎԍՋԍฎ ᦇᓒଘݣ ޫҘ ᦇᓒଘݣฎࣁኪᚏӾᬩᤈଫአᑕଧҁ᫫կ҂ጱሾह҅۱ೡ Ꮭկሾह ޾ ᫫կሾह ̶Ӟᛱᔮᕹଘݣ ۱ೡӞݣኪᚏጱᏝկ֛ᔮᕮ຅̵඙֢ᔮᕹ̵ᬩᤈ෸ପ̶ Java ฎள᭛҅ਞݢ޾قᶌጱ̶ ՗ᒟᦕ๜ኪᚏکහഝӾஞ҅՗჋౭๢کᑀ਍᩻ᕆᦇᓒ๢҅՗ಋ๢ک԰ᘶ ᗑ҅Java ෫॒ӧࣁѺJava Ԇᥝړԅӣӻᇇ๜ JavaSE(J2SE)(Java2 Platform Standard Edition҅javaଘݣຽٵᇇ҂ JavaEE(J2EE)(Java 2 Platform,Enterprise Edition҅javaଘݣմӱᇇ) JavaME(J2ME)(Java 2 Platform Micro Edition҅javaଘݣஙࣳᇇ)̶ Java ጱᇙᅩ Java ฎӞᳪ ᶎݻ੒᨝ ጱᖫᑕ᧍᥺ Ջԍฎᶎݻ੒᨝Ҙ ᶎݻ੒᨝(Object Oriented) ฎӞᐿ᫫կ୏ݎ௏మ̶ਙฎ੒ሿਫӮኴጱӞᐿು᨝҅ ᶎݻ੒᨝տ಩ፘىጱහഝ޾ොဩᕟᕢԅӞӻෆ֛๶፡இ̶ ፘ੒ጱݚक़Ӟᐿ୏ݎ௏మ੪ฎᶎݻᬦᑕጱ୏ݎ௏మ҅ՋԍᶎݻᬦᑕҘ ᶎݻᬦᑕ(Procedure Oriented) ฎӞᐿզᬦᑕԅӾஞጱᖫᑕ௏మ̶Ԉӻֺৼғྲই֦ฎӻ਍ኞ֦҅ྯॠ݄Ӥ਍ᵱᥝ؉پկ ԪఘҘ ᩸ଥ̵ᑯᤏ๐̵။᚜ڬᇌ҅ݰ݄ᷳ҅਍̶໊Ӟᛱฎᶲଧ௔ጱਠ౮Ӟᔮ̶֢ۖڜ ᘒᶎݻ੒᨝ݢզ಩਍ኞᬰᤈು᨝҅ಅզᬯӻֺৼ੪տݒԅ զӧአӸ໒ೲᆙᶲଧ๶ಗᤈྯӻ̶֢ۖᬯฎᇙᅩӞ̶ݢ Java ൷୒ԧ C++ Ӿᵙզቘᥴጱग़ᖀಥ̵೰ᰒ̵ٖਂᓕቘᒵ༷ஷҔӧአಋۖᓕቘ੒᨝ጱኞޮ޸๗҅ ᬯฎᇙ஄ԫ̶ Java ᧍᥺ٍํۑᚆ୩य़޾ᓌܔฃአӷӻᇙ஄҅ሿࣁմӱᕆ୏҅ݎள᭛භഠ୏҅ݎ੦ٌฎݱᐿ໛ຝ ጱڊሿֵ҅ Java ౮ԅ᩼๶᩼ᅉጱӞᳪ᧍᥺̶ᬯฎᇙᅩӣ̶ Java ฎӞᳪᶉா᧍᥺҅ᶉா᧍᥺೰ጱ੪ฎࣁᖫᦲ๗ᳵ੪ᚆड़Ꭳ᭲හഝᔄࣳጱ᧍᥺҅ࣁᬩᤈڹ੪ᚆ ड़༄ັᔄࣳጱྋᏟ௔҅Ӟ෮ᔄࣳᏟਧݸ੪ӧᚆٚๅද҅ྲইӥᶎᬯӻֺৼ̶ class student { void student_wakeUp(){...} void student_cloth(){...} void student_wash(){...} void student_eating(){...} void student_gotoSchool(){...} } 1 2 3 4 5 6 7 class student(){ void wakeUp(){...} void cloth(){...} void wash(){...} void eating(){...} void gotoSchool(){...} } 1 2 3 4 5 6 7 ᶉா᧍᥺Ԇᥝํ Pascal, Perl, C/C++, JAVA, C#, Scala ᒵ̶ ፘ੒ଫጱ҅ۖா᧍᥺ဌํձ֜ᇙਧጱఘ٭ᵱᥝ೰ਧݒᰁጱᔄࣳ҅ࣁᬩᤈ෸Ꮯਧጱහഝᔄ̶ࣳྲইํLisp, Perl, Python̵Ruby̵JavaScript ᒵ̶ ՗ᦡᦇጱ᥯ଶӤ๶᧔҅ಅํጱ᧍᥺᮷ฎᦡᦇአ๶಩Ոᔄݢ᧛ጱդᎱ᫨ഘԅ๢࢏೰ե̶ۖா᧍᥺ฎԅԧᚆ ड़ᦏᑕଧާ൉ṛᖫᎱපሲ҅ࢩྌ֦ݢզֵአๅ੝ጱդᎱ๶ਫሿۑᚆ̶ᶉா᧍᥺ᦡᦇฎአ๶ᦏᏝկಗᤈጱ ๅṛප҅ࢩྌᵱᥝᑕଧާᖫٟٵᏟ෫᧏ጱդᎱ҅զྌ๶ᦏ֦ጱդᎱੱளጱಗᤈ̶՗ᬯӻ᥯ଶ๶᧔҅ᶉா ᧍᥺ጱಗᤈපሲᥝྲۖா᧍᥺ṛ҅᭛ଶๅள̶ᬯฎᇙᅩ̶ࢥ Java ٍํଘݣᇿᒈ௔ݢ޾ᑏ༙௔ Java ํӞݙᶋଉ៪ݷጱݩݗғ Write once, run anywhere ҅Ԟ੪ฎӞེᖫ̵ٟ॒کᬩᤈ̶ԅՋԍ Java ᚆड़ڊޖᬯᐿᇍಢጱݩݗ๶Ҙ໐ஞ੪ฎ JVM ̶౯ժᎣ᭲҅ᦇᓒ๢ଫአᑕଧ޾Ꮭկԏᳵտ੽ᠰஉग़ ᕡᜓ҅ਙժԏᳵׁᶌ඙֢ᔮᕹਠ౮᧣ଶܐ޾᧣҅य़ᛘጱ֛ᔮᕮ຅ইӥ ᮎԍےӤ Java ଫአ̵JVM ጱ֛ᔮᕮ຅տݒԅইӥ public void foo() { int x = 5; boolean b = x; } 1 2 3 4 Java ฎ᪜ଘݣጱ҅૪ᖫᦲጱ Java ᑕଧݢզࣁձ֜ଃํ JVM ጱଘݣӤᬩᤈ̶֦ݢզࣁ Windows ଘݣ ӥᖫٟդᎱ҅ᆐݸ೭ک Linux ଘݣӥᬩᤈ҅ᧆই֜ਫሿޫҘ Ḓ֦ضᵱᥝࣁଫአӾᖫٟ Java դᎱҔ አ Eclipse ౲ᘏ javac ಩ Java դᎱᖫᦲԅ .class ෈կҔ ᆐݸ಩֦ጱ .class ෈կ಑౮ .jar ෈կҔ ᆐ֦ݸጱ .jar ෈կ੪ᚆड़ࣁ Windows ̵Mac OS X̵Linux ᔮᕹӥᬩᤈԧ̶ӧݶጱ඙֢ᔮᕹํӧݶጱ JVM ਫሿ҅ڔഘଘݣ෸҅ӧᵱᥝེٚᖫᦲ֦ጱ Java դᎱԧ̶ᬯฎᇙᅩԲ̶ Java ᚆड़਻ฃਫሿग़ᕚᑕ Java ฎӞᳪṛᕆ᧍᥺҅ṛᕆ᧍᥺տ੒አಁ੽ᠰஉग़ବ੶ਫሿᕡᜓ̶ྲই Java ฎই֜ਫሿग़ᕚᑕጱ̶՗ ඙֢ᔮᕹጱ᥯ଶ๶᧔҅ਫሿग़ᕚᑕጱොୗԆᥝํӥᶎᬯپᐿ አಁᑮᳵӾਫሿग़ᕚᑕࣁ ໐ᑮᳵӾਫሿग़ᕚᑕٖࣁ ਫሿᕚᑕݳ໐ᑮᳵӾႰٖ޾አಁࣁ ᘒ౯ᦊԅ Java ଫᧆฎࣁ አಁᑮᳵ ਫሿጱग़ᕚᑕٖ҅໐ฎఽᎣӧک Java ਂࣁग़ᕚᑕ๢ګጱ̶ᬯฎᇙ ᅩ̶م Java ٍํṛ௔ᚆ ౯ժᖫٟጱդᎱ҅ᕪᬦ javac ᖫᦲ࢏ᖫᦲᑍԅ ਁᜓᎱ(bytecode) ҅ᕪᬦ JVM ્ٖጱᥴ᯽࢏ਖ਼ਁᜓᎱ ᫨ഘԅ๢࢏դᎱ҅ᬯฎᥴ᯽ಗᤈ҅ᬯᐿ᫨ഘᬦᑕපሲ᫾̶֗֕ฎ᮱ړ JVM ጱਫሿྲই Hotspot JVM ᮷൉׀ԧ JIT(Just-In-Time) ᖫᦲ҅࢏Ԟ੪ฎ᭗ଉಅ᧔ጱۖாᖫᦲ︎҅࢏JIT ᚆड़ࣁᬩᤈ෸ਖ਼︎ᅾᅩդ Ꮁᖫᦲ๢࢏Ꮁ҅ᬯᐿොୗᬩᤈපሲྲ᫾ṛ҅ᬯฎᖫᦲಗᤈ̶ಅզ Java ӧՐՐݝฎӞᐿᥴ᯽ಗᤈጱ᧍ ᥺̶ᬯฎᇙᅩӠ̶ Java ᧍᥺ٍํ؋ौ௔ Java ጱ୩ᔄࣳ๢̵ګ୑ଉ॒ቘ̵࣯࣍ጱᛔۖතᵞᒵฎ Java ᑕଧ؋ौ௔ጱ᯿ᥝכᦤ̶ᬯԞฎ Java Ө C ᧍᥺ጱ᯿ᥝ̶ڦ܄ᬯฎᇙᅩ̶ك Java உ਻ฃ୏ړݎ૲ୗᶱፓ Java ᧍᥺ඪ೮ Internet ଫአጱ୏҅ݎJava Ӿํ net api҅ਙ൉׀ԧአԭᗑᕶଫአᖫᑕጱᔄପ҅۱ೡ URL̵URLConnection̵Socket̵ServerSocketᒵ̶Javaጱ RMIҁᬱᑕොဩᄶၚ҂ ๢ګԞฎ୏ړݎ૲ ୗଫአጱ᯿ᥝಋྦྷ̶ᬯฎᇙᅩԜ̶ Java ୏ݎሾह JDK JDKҁJava Development Kit҂ ᑍԅ Java ୏۱ݎ౲ Java ୏ݎૡٍ҅ฎӞӻᖫٟ Java ጱ Applet ੜᑕଧ޾ଫአᑕଧጱᑕଧ୏ݎሾह̶JDKฎෆӻJavaጱ໐ஞ҅۱ೡԧ JavaᬩᤈሾहҁJava Runtime Environment҂ ҅ӞԶ Java ૡٍ Java ጱ໐ஞᔄପҁJava API҂ ޾ ̶ ౯ժݢզᦊ፥ᎸᑪӞӥᬯୟ҅ࢶਙپԒ۱ೡԧ Java Ӿಅํጱ༷ஷ҅౯ֵአጱฎ jdk1.8 զᅩᬰ݄ݢ҅ Description of Java Conceptual Diagram ԭ Java ጱൈᬿىሿᬯ᯾ᶎ۱ೡԧಅํݎզݢ ҅ Oracle ൉׀ԧӷᐿ Java ଘݣጱਫሿ҅Ӟᐿฎ౯ժӤᶎ᧔ጱ JDK҅Java ୏ݎຽٵૡٍ۱҅Ӟᐿฎ JRE҅ݞ؉Java Runtime Environment҅Java ᬩᤈ෸ሾह̶JDK ጱۑᚆᥝྲ JRE قஉग̶़ JRE JRE ฎӻᬩᤈሾह҅JDK ฎӻ୏ݎሾह̶ࢩྌٟ Java ᑕଧጱ෸ײᵱᥝ JDK҅ᘒᬩᤈ Java ᑕଧጱ෸ײ ੪ᵱᥝJRE̶ᘒ JDK ᯾ᶎ૪ᕪ۱ތԧJRE҅ࢩྌݝᥝਞᤰԧJDK҅੪ݢզᖫᬋ Java ᑕଧ҅Ԟݢզྋଉ ᬩᤈ Java ᑕଧ̶֕ኧԭ JDK ۱ތԧᦜग़Өᬩᤈ෫ىጱٖ਻҅ܛአጱᑮᳵ᫾य़҅ࢩྌᬩᤈฦ᭗ጱ Java ᑕଧ෫ᶳਞᤰ JDK҅ᘒݝᵱᥝਞᤰ JRE ̶ݢܨ Java ୏ݎሾहᯈᗝ ᬯӻࣈොӧٚग़᧔ԧ҅ᗑӤํஉग़රᑕᯈᗝጱᩒා݇׀ݢᘍ̶ Java च๜᧍ဩ ࢩզٟ Java դᎱԧ҅ݢ੪҅ݸૡٍҁEclipse̵IDEA ᒵ҂ݎሾह҅ଚӥ᫹ Java ୏ݎᯈᗝਠ Java ୏ࣁ ԅ๜ᓤ෈ᒍฎ՗१༂ቘ Java ֛ᔮ҅ಅզํ஠ᥝ՗चᏐጱ༷ஷ୏ত᧨̶᩸ හഝᔄࣳ ํݝJava Ӿ҅හഝᔄࣳ ࣁ ᐿكᔄࢥ ෆහࣳғbyte̵short̵int̵long byte Ԟ੪ฎਁᜓ҅1 byte = 8 bits҅byte ጱἕᦊ꧊ฎ 0 Ҕ short ܛአӷӻਁᜓ҅Ԟ੪ฎ 16 ֖҅1 short = 16 bits҅ਙጱἕᦊ꧊Ԟฎ 0 Ҕ int ܛአࢥӻਁᜓ҅Ԟ੪ฎ 32 ֖҅1 int = 32 bits҅ἕᦊ꧊ฎ 0 Ҕ long ܛአكӻਁᜓ҅Ԟ੪ฎ 64 ֖҅1 long = 64 bits҅ἕᦊ꧊ฎ 0LҔ ಅզෆහࣳጱܛአਁᜓय़ੜᑮᳵԅ long > int > short > byte ၶᅩࣳ ၶᅩࣳํӷᐿහഝᔄࣳғfloat ޾ double float ฎܔᔜଶၶᅩࣳ҅ܛአ 4 ֖҅1 float = 32 bits҅ἕᦊ꧊ฎ 0.0fҔ double ฎ݌ᔜଶၶᅩࣳ҅ܛአ 8 ֖҅1 double = 64 bits҅ἕᦊ꧊ฎ 0.0dҔ ਁᒧࣳ ਁᒧࣳ੪ฎ char҅char ᔄࣳฎӞӻܔӞጱ 16 ֖ Unicode ਁᒧ๋҅ੜ꧊ฎ \u0000 (Ԟ੪ฎ 0 ) ҅ ๋य़꧊ฎ \uffff (ܨԅ 65535) ҅char හഝᔄࣳݢզਂؙձ֜ਁᒧֺ҅ই char a = 'A'̶ ૲ਫ਼ࣳ ૲ਫ਼ࣳ೰ጱ੪ฎ boolean҅boolean ํݝӷᐿ꧊҅true ౲ᘏฎ false҅ݝᤒᐏ 1 ֖҅ἕᦊ꧊ฎ false̶ զӤ x ֖ ᮷೰ጱฎਂٖࣁӾጱܛአ̶ चᏐ᧍ဩ य़ੜٟභఽғJava ฎ੒य़ੜٟභఽጱ᧍᥺ֺ҅ই Hello Ө hello ฎӧݶጱ҅ᬯٌਫ੪ฎ Java ጱਁ ᒧԀᤒᐏොୗ ᔄݷғ੒ԭಅํጱᔄ๶᧔҅Ḓਁྮଫᧆय़ֺٟ҅ই MyFirstClass ᦤੜֺٟ҅ই my.first.packageכଫᧆੱᰁݷғ۱ݷ۱ ොဩݷғොဩݷḒਁྮᵱᥝੜٟ҅ݸᶎྯӻܔ᦯ਁྮ᮷ᵱᥝय़ֺٟ҅ই myFirstMethod() ᬩᓒᒧ ᬩᓒᒧӧݝ Java Ӿํٌ҅՜᧍᥺Ԟํᬩᓒᒧ҅ᬩᓒᒧฎӞԶᇙྛጱᒧ҅ݩԆᥝአԭහ਍ڍහ̵ӞԶᔄ ࣳጱᩙ꧊᧍޾ݙ᭦ᬋྲ᫾ොᶎ҅౯ժ੪զ Java ԅֺ҅๶፡Ӟӥᬩᓒᒧ̶ ᩙ꧊ᬩᓒᒧ ᩙ꧊ᬩᓒᒧֵአ඙֢ᒧ = ๶ᤒᐏ҅ਙጱ఺௏ฎ಩ = ݦݩᬟጱ꧊॔ګᕳૢᬟ҅ݦᬟጱ꧊ݢզฎձ֜ଉ හ̵ݒᰁ౲ᘏᤒᬡୗ҅֕ૢᬟጱ꧊஠ᶳฎӞӻกᏟጱ҅૪ᕪਧԎጱݒᰁ̶ྲই int a = 4 ̶ ֕ฎ੒ԭ੒᨝๶᧔҅॔ګጱӧฎ੒᨝ጱ꧊҅ᘒฎ੒᨝ጱ୚አ҅ಅզইຎ᧔ਖ਼Ӟӻ੒᨝॔ګᕳݚӞӻ੒ ᨝҅ਫᴬӤฎਖ਼Ӟӻ੒᨝ጱ୚አᩙ꧊ᕳݚӞӻ੒᨝̶ ᓒහᬩᓒᒧ ᓒහᬩᓒᒧ੪޾හ਍Ӿጱහ꧊ᦇᓒ૧ӧग़҅Ԇᥝํ ᓒහᬩᓒᒧᵱᥝဳ఺ጱ੪ฎ սضᕆᳯ᷌ ҅୮ӞӻᤒᬡୗӾਂࣁग़ӻ඙֢ᒧ෸҅඙֢ᒧጱսضᕆᶲଧ੪ ٬ਧԧᦇᓒᶲଧ๋҅ᓌܔጱᥢڞ੪ฎضԙᴻ҅ٺےݸ () ጱսضᕆ๋ṛ҅ဌ஠ᥝᦕ֘ಅํጱսضᕆᶲ ଧ҅ӧᏟਧጱፗളአ () ੪ݢզԧ̶ ᛔी̵ᛔٺᬩᓒᒧ ᬯӻ੪ӧ෈ਁᥴ᯽ԧ҅ᥴ᯽ӧইፗള፡ֺৼกጮ ྲ᫾ᬩᓒᒧ ྲ᫾ᬩᓒᒧአԭᑕଧӾጱݒᰁԏᳵ҅ݒᰁ޾ᛔݒᰁԏᳵզٌ݊՜ᔄࣳጱמ௳ԏᳵጱྲ᫾̶ ྲ᫾ᬩᓒᒧጱᬩᓒᕮຎฎ boolean ̶ࣳ୮ᬩᓒᒧ੒ଫጱىᔮ౮ᒈ෸҅ᬩᓒጱᕮຎԅ true҅ڞވԅ false̶ྲ᫾ᬩᓒᒧ6 ํو ӻ҅᭗ଉ֢ԅڣෙጱׁഝአԭ๵կ᧍ݙӾ̶ ᭦ᬋᬩᓒᒧ ᭦ᬋᬩᓒᒧԆᥝํӣᐿ҅Ө̵౲̵ᶋ ӥᶎฎ᭦ᬋᬩᓒᒧ੒ଫጱ true/false ᒧݩᤒ int a = 5; b = ++a; c = a++; 1 2 3 ೲ֖ᬩᓒᒧ ೲ֖ᬩᓒᒧአ๶඙֢ෆහच๜ᔄࣳӾጱྯӻ ྲᇙ ֖҅Ԟ੪ฎԫᬰ̶֖ګೲ֖඙֢ᒧտ੒ӷӻ݇හӾ੒ ଫጱ֖ಗᤈ૲ਫ਼դහᬩᓒ҅ଚ๋ᕣኞ౮Ӟӻᕮຎ̶ ইຎᬰᤈྲ᫾ጱ݌ොฎහਁጱᦾ҅ᮎԍᬰᤈྲ᫾੪տݒԅೲ֖ᬩᓒ̶ ೲ֖Өғೲ֖ᬰᤈӨᬩᓒҁAND҂҅ӷӻ඙֢හӾ֖᮷ԅ1҅ᕮຎ಍ԅ1҅ڞވᕮຎԅ0̶ᵱᥝḒض಩ྲ ᫾݌ො᫨ഘ౮ԫᬰٚګೲྯӻ֖ᬰᤈྲ᫾ ೲ֖౲ғೲ֖ᬰᤈ౲ᬩᓒҁOR҂҅ӷӻ֖ݝᥝํӞӻԅ1҅ᮎԍᕮຎ੪ฎ1҅ڞވ੪ԅ0̶ ೲ֖ᶋғೲ֖ᬰᤈ୑౲ᬩᓒҁXOR҂҅ইຎ֖ԅ0҅ᕮຎฎ1҅ইຎ֖ԅ1҅ᕮຎฎ0̶ ೲ֖୑౲ғೲ֖ᬰᤈݍݐᬩᓒҁNOT҂҅ӷӻ඙֢හጱ֖Ӿ҅ፘڞݶᕮຎԅ0҅ӧڞݶᕮຎԅ1̶ ᑏ֖ᬩᓒᒧ ᑏ֖ᬩᓒᒧአ๶ਖ਼඙֢හݻ຤ӻොݻҁૢݻ౲ᘏݦ҂ᑏۖ೰ਧጱԫᬰ֖ګහ̶ ӣزᬩᓒᒧ ӣزᬩᓒᒧฎᔄ֒ if...else... ᬯᐿጱ඙֢ᒧ҅᧍ဩԅғ๵կᤒᬡୗҘᤒᬡୗ 1ғᤒᬡୗ 2̶ᳯݩ ෙᕮຎԅ૲ਫ਼ࣳ҅ԅ true ෸᧣አᤒᬡୗ 1҅ԅ false ෸᧣አᤒᬡୗ 2̶ڣෙጱ๵կ҅ڣᶎጱ֖ᗝฎڹ Java ಗᤈഴၞګᑕ Java Ӿጱഴၞګᑕٌਫ޾ C Ӟ໏҅ࣁ Java Ӿ҅ၞᑕഴګտၿ݊۱کೡ if-else̵while̵do-while̵ for̵return̵break զ݊ᭌೠ᧍ݙ switch ̶ӥᶎզྌᬰᤈړຉ ๵կ᧍ݙ ๵կ᧍ݢݙ໑ഝӧݶጱ๵կಗᤈӧݶጱ᧍۱̶ݙೡ if ๵կ᧍ݙӨ switch ग़ړඪ᧍̶ݙ if ๵կ᧍ݙ if ᧍ݢݙզܔᇿڣෙᤒᬡୗጱᕮຎ҅ᤒᐏᤒᬡጱಗᤈᕮຎֺ҅ই if...else ๵կ᧍ݙ if ᧍ݙᬮݢզӨ else ᬳአ҅᭗ଉᤒሿԅ ইຎჿ᪃຤ᐿ๵կ҅੪ᬰᤈ຤ᐿ॒ቘ҅ڞވ੪ᬰᤈݚӞᐿ॒ ቘ̶ if ݸጱ () ٖጱᤒᬡୗ஠ᶳฎ boolean ࣳጱ̶ইຎԅ true҅ڞಗᤈ if ݸጱ॔ݳ᧍ݙҔইຎԅ false҅ڞಗ ᤈ else ݸጱ॔ݳ᧍̶ݙ if...else if ग़ړඪ᧍ݙ ӤᶎӾጱ if...else ฎړܔඪ޾ӷӻړඪጱڣෙ҅ইຎํग़ӻڣෙ๵կ҅੪ᵱᥝֵአ if...else if switch ग़ړඪ᧍ݙ int a = 10; if(a > 10){ return true; } return false; 1 2 3 4 5 int a = 10; int b = 11; if(a >= b){ System.out.println("a >= b"); }else{ System.out.println("a < b"); } 1 2 3 4 5 6 7 int x = 40; if(x > 60) { System.out.println("xጱ꧊य़ԭ60"); } else if (x > 30) { System.out.println("xጱ꧊य़ԭ30֕ੜԭ60"); } else if (x > 0) { System.out.println("xጱ꧊य़ԭ0֕ੜԭ30"); } else { System.out.println("xጱ꧊ੜԭᒵԭ0"); } 1 2 3 4 5 6 7 8 9 10 Ӟᐿྲ if...else if ᧍ݙๅսᵝጱොୗฎֵአ switch ग़ړඪ᧍҅ݙਙጱᐏֺইӥ ஗ሾ᧍ݙ ஗ሾ᧍ݙ੪ฎࣁჿ᪃Ӟਧጱ๵կӥ॔ݍಗᤈ຤Ӟᤒᬡୗጱ඙֢҅ፗکჿ᪃஗ሾ᧍ݙጱᥝ࿢̶ֵአጱ஗ሾ ᧍ݙԆᥝํ for̵do...while() ̵ while ҅ while ஗ሾ᧍ݙ while ஗ሾ᧍ݙጱ஗ሾොୗԅڥአӞӻ๵կ๶ഴګฎވᥝᖀᖅ॔ݍಗᤈᬯӻ᧍̶ݙwhile ஗ሾ᧍ݙጱ໒ୗ ইӥ ਙጱތԎฎ҅୮ (૲ਫ਼꧊) ԅ true ጱ෸҅ײಗᤈӥᶎጱᤒᬡୗ҅૲ਫ਼꧊ԅ false ጱ෸҅ײᕮ๳஗ሾ҅૲ਫ਼ ꧊ٌਫԞฎӞӻᤒᬡୗ҅ྲই do...while ஗ሾ switch (week) { case 1: System.out.println("Monday"); break; case 2: System.out.println("Tuesday"); break; case 3: System.out.println("Wednesday"); break; case 4: System.out.println("Thursday"); break; case 5: System.out.println("Friday"); break; case 6: System.out.println("Saturday"); break; case 7: System.out.println("Sunday"); break; default: System.out.println("No Else"); break; } 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 while(૲ਫ਼꧊){ ᤒᬡୗ } 1 2 3 int a = 10; while(a > 5){ a--; } 1 2 3 4 while Ө do...while ஗ሾጱࠔӞڦ܄ฎ do...while ᧍ݙᛗ੝ಗᤈӞֵེ҅ܨᒫӞེጱᤒᬡୗԅ false̶ᘒ ਫᴬଫአӾ҅while ᥝྲࣁ໑๜ӧտಗᤈ̶ݙwhile ஗ሾӾ҅ইຎᒫӞེ๵կԅ false҅ᮎԍٌӾጱ᧍ ࣁ do...while ଫአጱๅଠ̶ਙጱӞᛱ୵ୗইӥ for ஗ሾ᧍ݙ for ஗ሾฎ౯ժᕪଉֵአጱ஗ሾොୗ҅ᬯᐿ୵ୗտࣁᒫӞེᬽդڹᬰᤈڡত۸̶ਙጱ୵ୗইӥ ྯེᬽդڹտၥᦶ૲ਫ਼ᤒᬡୗ̶ইຎ឴஑ጱᕮຎฎ false҅੪տಗᤈ for ᧍ݸݙᶎጱդᎱҔྯེ஗ሾᕮ ๳҅տೲᆙྍᬰጱ꧊ಗᤈӥӞེ஗ሾ̶ ᭖ݩ඙֢ᒧ ᬯ᯾ӧݢ஺ኼጱӞӻ੪ฎ᭖ݩ඙֢ᒧ҅Java ᯾ࠔӞአک᭖ݩ඙֢ᒧጱ੪ฎ for ஗ሾഴګ᧍ࣁ̶ݙᤒᬡୗ ጱڡত۸᮱ݢ҅ړզֵአӞᔮڜጱ᭖ړݩᵍጱ᧍ݙҔ᭗ᬦ᭖ݩ඙֢ᒧ҅ݢզࣁ for ᧍ٖݙਧԎग़ӻݒ ᰁ҅֕ਙժ஠ᶳٍํፘݶጱᔄࣳ for-each ᧍ݙ for-each ܨᬰᤈ᭭ܲጱොဩ҅ݳᵞ޾੒හᕟ׎ᓌ၄ጱ̵ොےԧӞᐿๅفJava JDK 1.5 Ӿᬮ୚ ࣁ ᧍ ৼইӥֺ҅ݙ ᪡᫨᧍ݙ Java ᧍᥺Ӿ҅ํӣᐿ᪡᫨᧍ݙ: break̵continue ޾ return break ᧍ݙ break ᧍ݙ౯ժࣁ switch Ӿ૪ᕪᥠکԧ҅ਙฎአԭᕣྊ஗ሾጱ඙֢҅ਫᴬӤ break ᧍ࣁݙfor̵while̵ do···while஗ሾ᧍ݙӾ҅አԭ୩ᤈᭅڊ୮ڹ஗ሾֺ҅ই int b = 10; // do···while஗ሾ᧍ݙ do { System.out.println("b == " + b); b--; } while(b == 1); 1 2 3 4 5 6 for(ڡত۸; ૲ਫ਼ᤒᬡୗ; ྍᬰ){}1 for(int i = 1;j = i + 10;i < 5;i++, j = j * 2){}1 int array[] = {7, 8, 9}; for (int arr : array) { System.out.println(arr); } 1 2 3 4 5 continue ᧍ݙ continue Ԟݢզනࣁ஗ሾ᧍ݙӾ҅ਙӨ break ᧍ํٍݙፘݍጱපຎ҅ਙጱ֢አฎአԭಗᤈӥӞེ஗ሾ҅ ᘒӧฎᭅڊ୮ڹ஗ሾ҅ᬮզӤᶎጱֺৼԅԆ return ᧍ݙ return ᧍ݢݙզ՗Ӟӻොဩᬬ҅ࢧଚ಩ഴګ๦Իᕳ᧣አਙጱ᧍̶ݙ ᶎݻ੒᨝ ӥᶎ౯ժ๶റᦎᶎݻ੒᨝ጱ௏మ҅ᶎݻ੒᨝ጱ௏మ૪ᕪ᭑ྍݐդԧᬦᑕ۸ጱ௏మ --- ᶎݻᬦᑕ҅Java ฎ ᶎݻ੒᨝ጱṛᕆᖫᑕ᧍᥺҅ᶎݻ੒᨝᧍᥺ٍํইӥᇙ஄ ᶎݻ੒᨝ฎӞᐿଉᥠጱ௏మ҅ྲ᫾ᒧݳՈժጱ௏ᘍԟబҔ ᶎݻ੒᨝ݢզਖ਼॔๥ጱӱۓ᭦ᬋᓌ۸҅ܔी୩դᎱ॔አ௔Ҕ ᶎݻ੒᨝ٍํು᨝̵੗ᤰ̵ᖀಥ̵ग़ாᒵᇙ௔̶ ᶎݻ੒᨝ጱᖫᑕ᧍᥺ԆᥝํғC++̵Java̵C#ᒵ̶ ಅզ஠ᶳᆧఀᶎݻ੒᨝ጱ௏మ಍ᚆᖫٟڊ Java ᑕଧ̶ ᔄԞฎӞᐿ੒᨝ ሿࣁ౯ժ๶ᦊᦩӞӻᶎݻ੒᨝ጱෛጱ༷ஷ --- ᔄ҅Ջԍฎᔄ҅ਙ੪ፘ୮ԭฎӞᔮڜ੒᨝ጱು᨝҅੪ྲই ԡᔁӞ໏҅ᔄፘ୮ԭฎԡጱ੗ᶎ҅य़ग़හᶎݻ੒᨝ጱ᧍᥺᮷ֵአ class ๶ਧԎᔄ҅ਙޞᦫ֦ਙ᯾ᶎਧ Ԏጱ੒᨝᮷ฎՋԍ໏ጱ҅౯ժӞᛱֵአӥᶎ๶ਧԎᔄ for(int i = 0;i < 10;i++){ if(i == 5){ break; } } 1 2 3 4 5 for(int i = 0;i < 10;i++){ System.out.printl(" i = " + i ); if(i == 5){ System.out.printl("continue ... "); continue; } } 1 2 3 4 5 6 7 8 public void getName() { return name; } 1 2 3 class ClassName { // body; } 1 2 3 դᎱྦྷӾၿ݊Ӟӻෛጱ༷ஷ // ҅ᬯӻ౯ժݸᶎտ᧔̶Ӥᶎ्֦҅กԧӞӻ class ᔄ҅ሿ֦҅ࣁ੪ݢ զֵአ new ๶ڠୌᬯӻ੒᨝ Ӟᛱ҅ᔄጱݷ޸᭽஗ ḧશܻڞ ҅ਙጱਧԎইӥ Ḱḧୗݷ޸ဩҁCamel-Case҂݈ᑍḧશୗݷ޸ဩ҅ฎኪᚏᑕୗᖫٟ෸ጱӞॺݷ޸ᥢڞҁబֺ҂̶ ྋইਙጱݷᑍ CamelCase ಅᤒᐏጱᮎ໏҅ฎ೰Ⴐֵݳአय़ੜٟਁྮ๶຅౮ݒᰁڍ޾හጱ̶ਁݷ ᑕଧާժԅԧᛔ૩ጱդᎱᚆๅ਻ฃጱݶࣁᤈԏᳵԻၞ҅ಅզग़᯻ݐᕹӞጱݢ᧛௔ྲ᫾অጱݷ޸ො ୗ̶ ੒᨝ጱڠୌ ܩ᮷፡֢ฎ੒᨝҅֕ฎ֦඙ᕒጱڔӞਧӧᴲኞ҅ੱᓕӞ֦מᦾፘݙJava Ӿ҅ӡԪӡᇔ᮷ฎ੒᨝̶ᬯ ࣁ ฎӞӻ੒᨝ጱ ୚አ(reference) ᫣፡֢ฎӞᕟ੒᨝޾ۺզ಩᫣ᰬݢғ֦ࡎᬯ᯾ํӞӻஉ୵᨝ጱྲࣁ̶ ୚አ޾੒᨝ጱᕟ̶ݳ୮֦మᥝ୏᫣ጱ෸֦҅ײḒضᵱᥝ೭ڊ᫣ᰬۺᅩڋ୏ᲁጱᭌᶱ҅؊᫣෸֦҅ᵱᥝᅩ ဌֵܨ୏ᲁ̶ଚӬ҅޾ᲁے๶ḝۖ᫣ጱۺፘ୮ԭ੪ฎ୚አ҅᫣੪ฎ੒᨝҅ኧ᫣ᰬۺᲁ๶ᲁ᫣̶᫣ᰬےڋ ํ᫣ጱਂ҅ࣁ᫣ᰬۺԞฎӞӻᇿᒈਂࣁጱਫ֛҅Ԟ੪ฎ᧔֦҅ํӞӻ੒᨝୚አ֦҅֕ӧӞਧᵱᥝӞӻ੒ ᨝Өԏىᘶ҅Ԟ੪ฎ ᬯ᯾ڠୌጱݝฎ୚አ҅ᘒଚᶋ੒᨝҅֕ฎইຎ֦మᥝֵአ s ᬯӻ୚አ෸҅տᬬࢧӞӻ୑ଉ҅ޞᦫ֦ᵱᥝ Ӟӻ੒᨝๶޾ᬯӻ୚አᬰᤈىᘶ̶Ӟᐿਞقጱ؉ဩฎ҅ڠࣁୌ੒᨝୚አ෸ݶ෸಩Ӟӻ੒᨝ᩙᕳਙ̶ ᘶ҅᭗ଉֵአ newىୌԧӞӻ୚አ҅੪૶๕ਙᚆӨӞӻෛጱ੒᨝ᬰᤈڠJava Ӿ҅Ӟ෮ ࣁ ඙֢ᒧ๶ਫ ሿᬯӞፓጱ̶new ጱ఺௏ฎ҅ᕳ౯Ӟӻෛ ੒᨝ ҅ইຎ֦ӧమፘՅ҅ᛔ૩ new Ӟӻ੒᨝੪অԧ̶ᐞ֦ ӥᬃৼଛᐰ̶ ં௔޾ොဩ ᔄӞӻ๋च๜ጱᥝᔰ੪ฎํં௔޾ොဩ̶ ં௔Ԟᤩᑍԅਁྦྷ҅ਙฎᔄጱ᯿ᥝᕟ౮᮱ં҅ړ௔ݢզฎձ఺ᔄࣳጱ੒᨝҅Ԟݢզฎच๜හഝᔄ̶ֺࣳ ইӥ ᔄӾᬮଫᧆ۱ೡොဩ҅ොဩᤒᐏጱฎ ؉຤ԶԪఘጱොୗ̶ොဩٌਫ੪ฎڍහ҅ݝӧᬦ Java ԟబ಩ڍහ ᑍԅොဩ̶ᬯᐿݞဩԞ֛ሿԧᶎݻ੒᨝ጱ༷ஷ̶ ොဩጱच๜ᕟ౮۱ೡ ොဩݷᑍ̵݇හ̵ᬬࢧ꧊޾ොဩ֛҅ ӥᶎฎਙጱᐏֺ ClassName classname = new ClassName();1 Car carKey;1 Car carKey = new Car();1 class A{ int a; Apple apple; } 1 2 3 4 ٌӾ҅ getResult ੪ฎොဩݷᑍ̵ () ᯾ᶎᤒᐏොဩളතጱ݇හ̵ return ᤒᐏොဩጱᬬࢧ꧊҅ဳ ఺ғොဩጱᬬࢧ꧊஠ᶳ޾ොဩጱ ݇හ ᔄࣳכ೮Ӟᛘ̶ํӞᐿᇙྛጱ݇හᔄࣳ --- void ᤒᐏොဩ෫ᬬ ꧊̶ࢧ {} ጱդᎱྦྷᤩᑍԅොဩ̶֛ތ۱ ຅᭜ොဩ Java Ӿ҅ํӞᐿᇙྛጱොဩᤩᑍԅ ຅᭜ොဩ ࣁ ҅Ԟᤩᑍԅ຅᭜ڍහ̵຅᭜࢏ᒵ̶ࣁ Java Ӿ҅᭗ᬦ ൉׀ᬯӻ຅᭜҅࢏๶Ꮯྯכӻ੒᨝᮷ᤩڡত۸̶຅᭜ොဩݝᚆࣁ੒᨝ጱڠୌ෸๗᧣አӞེ҅כᦤԧ੒᨝ ೮Ӟᛘ҅ଚӬ຅᭜כݷᔄ޾ᑍᥝݷ꧊҅ਙጱࢧᬬ޾ত۸ጱᬰᤈ̶຅᭜ොဩྲ᫾ᇙྛ҅ਙဌํ݇හᔄࣳڡ ොဩݢզํग़ӻ҅ӥᶎฎӞӻ຅᭜ොဩጱᐏֺ ӤᶎਧԎԧӞӻ Apple ᔄ֦҅տݎሿᬯӻ Apple ᔄဌํ݇හᔄࣳ޾ᬬࢧ꧊҅ଚӬํग़ӻզ Apple ݷݶ ጱොဩ҅ᘒӬݱӻ Apple ጱ݇හڜᤒ᮷ӧӞ໏҅ᬯٌਫฎӞᐿग़ாጱ֛ሿ҅౯ժݸᶎտ᧔̶ࣁਧԎਠ౮ ຅᭜ොဩ҅ݸ౯ժ੪ᚆड़ڠୌ Apple ੒᨝ԧ̶ ইӤᶎಅᐏ҅౯ժਧԎԧࢥӻ Apple ੒᨝҅ଚ᧣አԧ Apple ጱࢥᐿӧݶጱ຅᭜ොဩٌ҅Ӿ҅ӧےձ֜ ݇හጱ຅᭜ොဩᤩᑍԅἕᦊጱ຅᭜ොဩ҅Ԟ੪ฎ ইຎᔄӾဌํਧԎձ֜຅᭜ොဩ҅ᮎԍ JVM տԅ֦ᛔۖኞ౮Ӟӻ຅᭜ොဩ҅ইӥ public int getResult(){ // ... return 1; } 1 2 3 4 class Apple { int sum; String color; public Apple(){} public Apple(int sum){} public Apple(String color){} public Apple(int sum,String color){} } 1 2 3 4 5 6 7 8 9 10 11 class createApple { public static void main(String[] args) { Apple apple1 = new Apple(); Apple apple2 = new Apple(1); Apple apple3 = new Apple("red"); Apple apple4 = new Apple(2,"color"); } } 1 2 3 4 5 6 7 8 9 10 Apple apple1 = new Apple();1 class Apple { 1 2 ӤᶎդᎱӧտݎኞᖫᦲᲙ᧏҅ࢩԅ Apple ੒᨝۱ތԧӞӻἕᦊጱ຅᭜ොဩ̶ ἕᦊጱ຅᭜ොဩԞᤩᑍԅἕᦊ຅᭜࢏౲ᘏ෫݇຅᭜̶࢏ ᬯ᯾ᵱᥝဳ఺Ӟᅩጱฎֵ҅ܨ JVM տԅ֦ἕᦊႲےӞӻ෫݇ጱ຅᭜֕҅࢏ฎইຎ֦ಋۖਧԎԧձ֜Ӟ ӻ຅᭜ොဩ҅JVM ੪ӧٚԅ֦൉׀ἕᦊጱ຅᭜֦҅࢏஠ᶳಋۖ೰ਧ҅ڞވտڊሿᖫᦲᲙ᧏̶ ดᐏጱᲙ᧏ฎ҅஠ᶳ൉׀ Apple ଃํ int ݇හጱ຅᭜ڍහ҅ᘒἕᦊጱ෫݇຅᭜ڍහဌํᤩ꧋ᦜֵአ̶ ොဩ᯿᫹ හٌ҅ڍԧ຅᭜کᤒሿ୵ୗ̶౯ժӤᶎ᧔ݶጱӧݷJava ӾӞӻஉ᯿ᥝጱ༷ஷฎොဩጱ᯿᫹҅ਙฎᔄ ࣁ ਫ຅᭜ڍහԞฎ᯿᫹ጱӞᐿ̶ݚक़Ӟᐿ੪ฎොဩጱ᯿᫹ int sum; String color; } class createApple { public static void main(String[] args) { Apple apple1 = new Apple(); } } 3 4 5 6 7 8 9 10 11 12 13 14 public class Apple { int sum; String color; public Apple(){} public Apple(int sum){} 1 2 3 4 5 6 7 ইӤᶎಅᐏ҅੪ํӷᐿ᯿᫹ጱොୗ҅Ӟᐿฎ Apple ຅᭜ڍහጱ᯿᫹҅Ӟᐿฎ getApple ොဩጱ᯿᫹̶ ֕ฎᬯ໏੪ၿ݊کӞӻᳯ᷌҅ᥝฎํپӻፘݶጱ҅ਁݷJava ই֜Ꭳ֦᭲᧣አጱฎߺӻොဩޫҘᬯ᯾ᦕ ֘Ӟᅩྯ҅ݢܨӻ᯿᫹ጱොဩ᮷ํᇿӞ෫ԫጱ݇හڜᤒ̶ٌӾ۱ೡ݇හጱᔄ̵ࣳᶲଧ̵݇හහᰁᒵ҅ჿ ᪃ӞᐿӞӻࢩᔰ੪຅౮ԧ᯿᫹ጱ஠ᥝ๵կ̶ ᧗ᦕ֘ӥᶎ᯿᫹ጱ๵կ ොဩݷᑍ஠ᶳፘ̶ݶ ݇හڜᤒ஠ᶳӧݶҁӻහӧ̵ݶ౲ᔄࣳӧ̵݇ݶහᔄࣳഭڜᶲଧӧݶᒵ҂̶ ොဩጱᬬࢧᔄࣳݢզፘݶԞݢզӧፘ̶ݶ ՐՐᬬࢧᔄࣳӧݶӧ᪃զ౮ԅොဩጱ᯿᫹̶ ᯿᫹ฎݎኞࣁᖫᦲ෸ጱ҅ࢩԅᖫᦲݢ࢏զ໑ഝ݇හጱᔄࣳ๶ᭌೠֵአߺӻොဩ̶ ොဩጱ᯿ٟ ොဩጱ᯿ٟӨ᯿᫹ᡱᆐਁݷஉፘ֒҅֕ܩਠقฎӧݶጱӳᥜ̶ොဩ᯿ٟጱൈᬿฎ੒ ৼᔄ޾ᆿᔄ ԏᳵ ጱ̶ᘒ᯿᫹೰ጱฎݶӞᔄӾጱ̶ֺইইӥդᎱ ӤᶎᬯྦྷդᎱൈᬿጱ੪ฎ᯿ٟጱդᎱ֦҅ݢզ፡҅کৼᔄ Apple Ӿጱොဩ޾ᆿᔄ Fruit Ӿጱොဩ҅ݷݶ ಅզ҅౯ժᚆड़വෙڊ᯿ٟጱܻڞ ᯿ٟጱොဩ஠ᶳᥝ޾ᆿᔄכ೮Ӟᛘ҅۱ೡᬬࢧ꧊ᔄࣳ,ොဩݷ,݇හڜᤒ Ԟ᮷Ӟ໏̶ ᯿ٟጱොဩݢզֵአ @Override ဳᥴ๶ຽᦩ ৼᔄӾ᯿ٟොဩጱᦢᳯ๦ᴴӧᚆ֗ԭᆿᔄӾොဩጱᦢᳯ๦ᴴ̶ public int getApple(int num){ return 1; } public String getApple(String color){ return "color"; } } 8 9 10 11 12 13 14 15 16 17 class Fruit { public void eat(){ System.out.printl('eat fruit'); } } class Apple extends Fruit{ @Override public void eat(){ System.out.printl('eat apple'); } } 1 2 3 4 5 6 7 8 9 10 11 12 13 14 ত۸ڡ ᔄጱڡত۸ Ӥᶎ౯ժڠୌڊ๶ԧӞӻ Car ᬯӻ੒᨝ٌ҅ਫֵࣁአ new ىᲫਁڠୌӞӻ੒᨝ጱ෸ٌ҅ײਫฎ᧣አԧ ᬯӻ੒᨝෫݇හጱ຅᭜ොဩᬰᤈጱڡত۸҅Ԟ੪ฎইӥᬯྦྷդᎱ ᬯӻ෫݇හጱ຅᭜ڍහݢզᵌᡐ҅ኧ JVM ᛔۖႲ̶ےԞ੪ฎ᧔҅຅᭜ڍහᚆड़Ꮯכᔄጱڡত۸̶ ౮ާڡত۸ Java տੱᰁכᦤྯӻݒᰁֵࣁአڹ᮷տ឴஑ڡত۸҅ڡত۸ၿ݊ӷᐿڡত۸̶ Ӟᐿฎᖫᦲ࢏ἕᦊ೰ਧጱਁྦྷڡত۸҅च๜හഝᔄࣳጱڡত۸ Ӟᐿฎٌ՜੒᨝ᔄࣳጱڡত۸҅String ԞฎӞᐿ੒᨝҅੒᨝ጱڡত꧊᮷ԅ null ٌ҅ӾԞ۱ೡच ๜ᔄࣳጱ۱ᤰᔄ̶ Ӟᐿฎ೰ਧහ꧊ጱڡত۸ֺ҅ই Ԟ੪ฎ᧔҅ ೰ਧ a ጱڡত۸꧊ӧฎ 0 ҅ᘒฎ 11̶ٌ՜च๜ᔄࣳ޾੒᨝ᔄࣳԞฎӞ໏ጱ̶ ຅᭜ڡ࢏ত۸ ত꧊ֺ҅ইڡত۸҅Ꮯਧڡ຤Զ֢ۖᬰᤈ޾๶੒຤Զොဩ࢏አ຅᭜ڥզݢ ত۸ԅ 11̶ڡහ҅ᚆड़಩ i ጱ꧊ڍአ຅᭜ڥ class Car{ public Car(){} } 1 2 3 int a = 111 public class Counter{ int i; public Counter(){ i = 11; } } 1 2 3 4 5 6 ত۸ᶲଧڡ Ḓضض๶፡ӞӥํߺԶᵱᥝറᦎጱڡত۸ᶲଧ ᶉாં௔ғstatic ୏१ਧԎጱં௔ ᶉாොဩࣘғ static {} ۱᩸๶ጱդᎱࣘ ฦ᭗ં௔ғ ᶋ static ਧԎጱં௔ ฦ᭗ොဩࣘғ {} ۱᩸๶ጱդᎱࣘ ຅᭜ڍහғ ᔄݷፘݶጱොဩ ොဩғ ฦ᭗ොဩ ᬯྦྷդᎱጱಗᤈᕮຎ੪ݍଫԧਙጱڡত۸ᶲଧ ᶉாં௔ڡত۸ ᶉாොဩڡࣘত۸ ฦ᭗ં௔ڡত۸ ฦ᭗ොဩڡࣘত۸ ຅᭜ڍහڡত۸ හᕟڡত۸ public class LifeCycle { // ᶉாં௔ private static String staticField = getStaticField(); // ᶉாොဩࣘ static { System.out.println(staticField); System.out.println("ᶉாොဩڡࣘত۸"); } // ฦ᭗ં௔ private String field = getField(); // ฦ᭗ොဩࣘ { System.out.println(field); } // ຅᭜ڍහ public LifeCycle() { System.out.println("຅᭜ڍහڡত۸"); } public static String getStaticField() { String statiFiled = "Static Field Initial"; return statiFiled; } public static String getField() { String filed = "Field Initial"; return filed; } // Ԇڍහ public static void main(String[] argc) { new LifeCycle(); } } 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 හᕟฎፘݶᔄࣳጱ̵አӞӻຽᦩᒧݷᑍ੗ᤰکӞ᩸ጱӞӻ੒᨝ଧڜ౲च๜ᔄࣳහഝଧ̶ڜහᕟฎ᭗ᬦො ೡݩӥຽ඙֢ᒧ [] ๶ਧԎֵአ̶ ӞᛱහᕟฎᬯԍਧԎጱ ӷᐿ໒ୗጱތԎฎӞ໏ጱ̶ ፗളᕳྯӻزᔰᩙ꧊ : int array[4] = {1,2,3,4}; ᕳӞ᮱ᩙړ꧊҅ݸᶎጱ᮷ԅ 0 ғ int array[4] = {1,2}; ኧᩙ꧊݇හӻහ٬ਧහᕟጱӻහ ғ int array[] = {1,2}; ᤒڜහ݇ݒݢ Java ӾӞᐿහᕟٯᳪጱአဩ੪ฎ හ݇ݒݢ හጱਧԎইӥ݇ݒݢ҅ ᆐݢ֦҅ݸզֵአӥᶎᬯپᐿොୗᬰᤈ݇ݒݢහጱ᧣አ ੒᨝ጱᲀྪ ᡱᆐ Java ᧍᥺ฎचԭ C++ ጱ҅֕ฎਙ޾ C/C++ Ӟӻ᯿ᥝጱᇙ஄੪ฎӧᵱᥝಋۖᓕቘ੒᨝ጱᲀྪૡ Ӟӻᥡᅩکቘᥴ Java ᡦ೙๢̾Ӿ൉فጱӞԡ ̽Ⴎݷ៪ࣁ̶֢ Java Ӿ҅౯ժӧٚᵱᥝಋۖᓕቘ੒᨝ጱᲀྪ҅ਙฎኧ Java ᡦ೙๢ ࣁ ᬰᤈᓕቘ޾ᲀྪጱ̶ᡱᆐ౯ժ ӧᵱᥝಋۖᓕቘ੒᨝҅֕ฎ֦ᵱᥝᎣ᭲ ੒᨝֢አऒ ᬯӻ༷ஷ̶ ੒᨝֢አऒ Jग़හ᧍᥺᮷ํ ֢አऒ(scope) ᬯӻ༷ஷ̶֢አऒ٬ਧԧٌٖ᮱ਧԎጱݒᰁݷጱݢᥠ௔޾ኞޮ޸๗̶ࣁ C̵C++ ޾ Java Ӿ֢҅አऒ᭗ଉኧ {} ጱ֖ᗝ๶٬ਧֺ҅ই int[] a1; //౲ᘏ int a1[]; 1 2 3 4 5 public int add(int... numbers){ int sum = 0; for(int num : numbers){ sum += num; } return sum; } 1 2 3 4 5 6 7 add(); // ӧփ݇හ add(1); // փ᭓Ӟӻ݇හ add(2,1); // փ᭓ग़ӻ݇හ add(new Integer[] {1, 3, 2}); // փ᭓හᕟ 1 2 3 4 a ݒᰁտࣁӷӻ {} ֢አऒٖํප҅ᘒ b ݒᰁጱ꧊ݝᚆࣁਙᛔ૩ጱ {} ٖํප̶ ᡱᆐਂ֢ࣁአऒ҅֕ฎӧ꧋ᦜᬯ໏ٟ ᬯᐿٟဩࣁ C/C++ Ӿฎݢզጱ҅֕ฎࣁ Java Ӿӧ꧋ᦜᬯ໏ٟ҅ࢩԅ Java ᦡᦇᘏᦊԅᬯ໏ٟտ੕ᛘᑕ ଧႰԤ̶ this ޾ super this ޾ super ᮷ฎ Java ӾጱىᲫਁ this ᤒᐏጱ୮ڹ੒᨝҅this ݢզ᧣አොဩ̵᧣አં௔޾೰ݻ੒᨝๜᫝̶this ࣁ Java ӾጱֵአӞᛱํӣ ᐿғ೰ݻ୮ڹ੒᨝ ᬯྦྷդᎱྲ᫾ᔜও҅ᔜও҅ޫߺࣁ౯Ӟӻ eatApple() ොဩᒌᆐݢզ᧣አग़ེ֦҅ݸࣁᶎᬮݢզᖀᖅ᧣ አ҅ᬯ੪உᐟ॰ԧ҅ԅޫࠨҘٌਫ੪ฎ this ֢ࣁᐠԧ҅౯ࣁ eatApple ොဩӾےԧӞӻ return this ጱᬬࢧ꧊҅Ԟ੪ฎ᧔ߺӻ੒᨝᧣አ eatApple ොဩ᮷ᚆᬬࢧ੒᨝ጱᛔ᫝̶ this ᬮݢզץ᷶ં௔๋҅ଉᥠጱ੪ฎࣁ຅᭜ොဩӾֵአ this ҅ইӥಅᐏ { int a = 11; { int b = 12; } } 1 2 3 4 5 6 { int x = 11; { int x = 12; } } 1 2 3 4 5 6 public class Apple { int i = 0; Apple eatApple(){ i++; return this; } public static void main(String[] args) { Apple apple = new Apple(); apple.eatApple().eatApple(); } } 1 2 3 4 5 6 7 8 9 10 11 12 13 14 main ොဩӾփ᭓ԧӞӻ int ꧊ԅ 10 ጱ݇හ҅ਙᤒᐏጱ੪ฎ᝘ຎጱහᰁ҅ଚ಩ᬯӻහᰁᩙᕳԧ num ق ੴݒᰁ̶ಅզ num ጱ꧊ሿࣁ੪ฎ 10̶ this ᬮݢզ޾຅᭜ڍහӞֵ᩸አ҅꧌୮ӞӻقੴىᲫਁጱපຎ ֦տݎሿӤᶎᬯྦྷդᎱֵአጱӧฎ this, ᘒฎ this(݇හ) ̶ਙፘ୮ԭ᧣አԧٌ՜຅᭜ොဩ҅ᆐݸփ᭓ ݇හᬰ̶݄ᬯ᯾ဳ఺Ӟᅩғthis() ஠ᶳනࣁ຅᭜ොဩጱᒫӞᤈ҅ڞވᖫᦲӧ᭗ᬦ public class Apple { private int num; public Apple(int num){ this.num = num; } public static void main(String[] args) { new Apple(10); } } 1 2 3 4 5 6 7 8 9 10 11 12 public class Apple { private int num; private String color; public Apple(int num){ this(num,"ᕁᜋ"); } public Apple(String color){ this(1,color); } public Apple(int num, String color) { this.num = num; this.color = color; } } 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 ইຎ֦಩ this ቘᥴԅ೰ݻᛔ᫝ጱӞӻ୚አ҅ᮎԍ super ੪ฎ೰ݻᆿᔄጱӞӻ୚አ̶super ىᲫਁ޾ this Ӟ໏֦҅ݢզֵአ super.੒᨝ ๶୚አᆿᔄጱ౮ާ҅ইӥ ֦Ԟݢզֵአ super(݇හ) ๶᧣አᆿᔄጱ຅᭜ڍහ҅ᬯ᯾ӧٚԈֺৼԧ̶ ӥᶎԅ֦࿤௛ԧ this ىᲫਁ޾ super ىᲫਁጱྲ᫾̶ public class Fruit { int num; String color; public void eat(){ System.out.println("eat Fruit"); } } public class Apple extends Fruit{ @Override public void eat() { super.num = 10; System.out.println("eat " + num + " Apple"); } } 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 ᦢᳯഴګ๦ᴴ ᦢᳯഴګ๦ᴴ݈ᑍԅ ੗ᤰ ҅ਙฎᶎݻ੒᨝ӣय़ᇙ௔ӾጱӞᐿ҅౯ԏࣁڹ਍ԟᬦᑕӾᕪଉտ஺ኼ੗ᤰ҅ ஞమᬯӧ੪ฎӞӻᦢᳯץ᷶ᒧԍ҅ெԍ੪ฎӣय़ᇙ௔ጱ஠ᥝ๵կԧҘݸ๶౯಍Ꭳ᭲҅ইຎ֦מձጱӥં ੒֦ᵌᎎ bug֦҅ฎ໑๜ӧᎣ᭲ጱ̶ ᦢᳯഴګ๦ᴴٌਫ๋໐ஞ੪ฎӞᅩғݝ੒ᵱᥝጱᔄݢᥠ̶ JavaӾ౮ާጱᦢᳯ๦ᴴࢥํوᐿ҅ڦړฎ public̵protected̵default̵private҅ਙժጱݢᥠ௔ইӥ ᖀಥ ᖀಥฎಅํ OOP(Object Oriented Programming) ᧍᥺޾ Java ᧍᥺᮷ӧݢ౲ᗌጱӞ᮱ݝ̶ړᥝ౯ ժڠୌԧӞӻᔄ҅੪ᵌୗጱᖀಥᛔ Object ᆿᔄ҅ݝӧᬦဌํ೰ਧ̶ইຎ֦ดᐏ೰ਧԧᆿᔄ҅ᮎԍ֦ ᖀಥԭᆿᔄ҅ᘒ֦ጱᆿᔄᖀಥԭ Object ᔄ̶ ᖀಥጱىᲫਁฎ extends ҅ইӤࢶಅᐏ҅ইຎֵአԧ extends ดᐏ೰ਧԧᖀಥ҅ᮎԍ౯ժݢզ᧔ Father ฎᆿᔄ҅ᘒ Son ฎৼᔄ҅አդᎱᤒᐏইӥ ᖀಥ݌ො೜ํ຤ᐿو௔ጱᇙ஄ ইຎ Son ဌํਫሿᛔ૩ጱොဩጱᦾ҅ᮎԍἕᦊ੪ฎአጱฎᆿᔄጱ feature ොဩ̶ইຎৼᔄਫሿԧᛔ ૩ጱ feature ොဩ҅ᮎԍ੪ፘ୮ԭฎ᯿ٟԧᆿᔄጱ feature ොဩ҅ᬯԞฎ౯ժӤᶎ൉کጱ᯿ٟԧ̶ ग़ா ग़ா೰ጱฎݶӞӻᤈԅٍํग़ӻӧݶᤒሿ୵ୗ̶ฎ೰Ӟӻᔄਫֺҁ੒᨝҂ጱፘݶොဩࣁӧݶఘ୵ӥٍํ ӧݶᤒሿ୵ୗ̶੗ᤰ޾ᖀಥฎग़ாጱचᏐ҅Ԟ੪ฎ᧔҅ग़ாݝฎӞᐿᤒሿ୵ୗᘒ૪̶ ই֜ਫሿग़ாҘग़ாጱਫሿٍํӣᐿ꧌ᥝ๵կ ᖀಥ ᯿ٟᆿᔄොဩ ᆿᔄ୚አ೰ݻৼᔄ੒᨝ class Father{} class Son extends Father{} 1 2 3 class Father{ public void feature(){ System.out.println("ᆿՅጱᇙ஄"); } } class Son extends Father { } 1 2 3 4 5 6 7 8 9 ྲইӥᶎᬯྦྷդᎱ ሿ mainݎզݢ֦ ොဩӾํӞӻஉᐟ॰ጱࣈො҅ Fruit fruit = new Apple() ҅Fruit ᔄࣳጱ੒᨝ ᒌᆐ೰ݻԧ Apple ੒᨝ጱ୚አ҅ᬯٌਫ੪ฎग़ா -> ᆿᔄ୚አ೰ݻৼᔄ੒᨝҅ࢩԅ Apple ᖀಥԭ Fruit҅ଚӬ᯿ٟԧ eat ොဩ҅ಅզᚆड़ᤒሿڊ๶ग़ᐿᇫாጱ୵ୗ̶ ᕟݳ ᕟٌݳਫӧᵙቘᥴ҅੪ฎਖ਼੒᨝୚አᗝԭෛᔄӾ̶ݢܨᕟݳԞฎӞᐿ൉ṛᔄጱ॔አ௔ጱӞᐿොୗ̶ইຎ ֦మᦏᔄٍํๅग़ጱಘ઀ۑᚆ֦҅ᵱᥝᦕ֘Ӟݙᦾग़አᕟ҅ݳ੝አᖀಥ̶ դᎱӾ SoccerPlayer ୚አԧ Soccer ᔄ҅᭗ᬦ୚አ Soccer ᔄ҅๶ᬡک᧣አ soccer Ӿጱં௔޾ොဩ̶ ᕟ޾ݳᖀಥฎํڦ܄ጱ҅ਙժጱԆᥝڦ܄ইӥ̶ public class Fruit { int num; public void eat(){ System.out.println("eat Fruit"); } } public class Apple extends Fruit{ @Override public void eat() { super.num = 10; System.out.println("eat " + num + " Apple"); } public static void main(String[] args) { Fruit fruit = new Apple(); fruit.eat(); } } 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 public class SoccerPlayer { private String name; private Soccer soccer; } public class Soccer { private String soccerName; } 1 2 3 4 5 6 7 8 9 10 11