CMBUkTI4 XøaepÞógpÞat;lkçx½NÐ 3

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1 JAVA Programming ChapterIV CMBUkTI4 XøaepÞógpÞat;lkçx½NÐ 3 XøaepÞógpÞat;lkçx½NÐenAkñúgPasa Java RtUv)anerobdak;eTAtamRbePTdUcCa³ Selection, Iteration nig Jump. XøaRbePT Selection GaceGaykmμviFIrbs;eyIgeRCIsyknUvtMeNIrRbtibtþikarepSgKña edayep keli lt plénkensammyy b spabéngbaøatiþmyy. XøaRbePT Iteration GaceGaykarRbtibtþikmμviFI efviskmμpab dedl²nuvxøamyy b ercin)an mann½yfa Iteration bgá)andmenirrgvil. XøaRbePT Jump GaceGaykmμviFI rbs;eyigrbtibtþikartamlkçn³minlmdab;lmeday. 1> XøaRbePT Selection én Java(Selection statement): Java pþl;nuvxøarbept selection cmnynbirkw³ if nig switch. XøaTaMgenHGaceGayeyIgepÞógpÞat;tMenIr karénkmμvifi Ep kelilkçx½nð EdlGacdwg)aneBldMeNIrkar. 1>1 Xøa If (If statement) Xøa If KWEckecjeTAtamlkçx½NÐrbs; Java. vagacerbismrab;namtmenirkarkmμvifi tampøúvbirepsg Kña. enhcatmrg;rbs;xøa If ³ if (condition) statement; else statement; kñúgenah statement nimyy² GacCaXøaeTalmYy b ercinxøa Edldak;kñúgsBaØa {. condition CatMélelxNa EdleGaytMélCa boolean. else CaXøaEdlGacCMerIl. cursegátxøakñúg]tahrn_xagerkam³ int a, b; //... if ( a < b ) a = 0; else b = 0; 1>1>1 Xøa If enakñug If myyetot (If in If) Xøa if myyenakñúg if myyetot KWCaXøa if myyedlcaplén if b else myy. kalna eyigdak; if myyenakñúg if myyetotenah bbaðasmxan;edlrtuvcamenah KW Xøa else myy Canic CakalsMedAeTArk if EdlCitbMput ehiysßitkñúg block duckña. enhca]tahrn_myy³ if ( i==10 ){ if ( j < 20 ) a = b; if ( k > 100 ) c = d; else else a = c; //this if is //associated with this else a = d; //this else refers to if ( i==10 ) Prepared by: Mr. Rin Ratha Cambodian University for Specialties

2 JAVA Programming ChapterIV 1>1>2 lmdab;fñak; if-else-if (If-else-If) karbegáitkmμvifituetamyy EdlmanmUldæanenAelIlMdab;tKñaénXøa if myyenakñúg if myy etot KWCalMdab; if-else-if. vamantmrg;ducxagerkam³ if (condition) statement; else if (condition) statement; else if (condition) else statement;. statement; enhcakmμvifimyyedlerbilmdab;fñak; if-else-if edim,ikmnt;faetiexnasßitenakñúgrduvna³ //demostrates if-else-if statements; class IfElse{ int month = 4; String season; if ( month ==12 month == 1 month == 2 ) season = "Winter"; else if ( month == 3 month == 4 month == 5 ) season = "Spring"; else if ( month ==6 month == 7 month == 8) season = "Summer"; else if ( month == 9 month == 10 month == 11) season = "Autumn"; else season = "Bogus Month"; System.out.println("April is in the " + season + "."); 1>2 Xøa switch (Switch statement) Xøa switch KWCaXøaEdlEckecjCaeRcInpøÚvenAkñúg Java. vapþl;mefüa)aygayrsylmyy edim,i bba ÚnkarRbtibtþieTAeGayEpñkepSgKña én code edayep kelitmélénkensamelx. vifienhpþl;nuvmefüa)ay myyetotedll CaXøa if-else-if. enhcatmrg;tuetaénxøa switch³ switch (expression){ case value1: //statement sequence break; case value2: //statement sequence break; Prepared by: Rin Ratha Cambodian University for Specialties

3 JAVA Programming ChapterIV. case valuen: //statement sequence break; default: //default statement sequence kñúgenah expression RtUvEtCaRbePT byte, short, int b char ehiytmélnimyy²edl)ankmnt;enakñúgxøa case nimyy² RtUvEtCaRbePTRtUvKñanwg expression. tmélrbs; case nimyy² RtUvEtCacMnYnefr minemncagbaøatþi. tmélrbs; case duckña KWminGnuBaØatþieGayeRbIeT. Xøa break RtUv)aneRbIenAkñúg switch edim,ibba b;lmdab;xaømyy. lkçn³enh GaceGaydMenIrkarecj putmkerka én switch. kmμvifixagerkamenhca]tahrn_tucmyybikarerbixøa switch³ //simple example of switch statement class SimpleSwitch{ for ( int i = 0; i<6; i++ ) switch ( i ){ case 0: System.out.println(" i is zero"); break; case 1: System.out.println(" i is one"); break; case 2: System.out.println(" i is two"); break; case 3: System.out.println(" i is three"); break; default: System.out.println(" i is greater than 3"); break; Xøa break manlkçn³cmeris erbik¾)an minerbik¾)an. ebieyiglub break karrbtibtþinwgbnþetakan; case bnþab;. CYnkalvaRtUvkarman case CaeRcInedaymineRbIXøa break enacenøah case TaMgenaH. ]TahrN_ cursegátkmμvifixagerkam³ // In a switch, break statements are optional. class MissingBreak{ for ( int i = 0; i<12; i++ ){ switch ( i ){ case 0: case 1: case 2: case 3: case 4: System.out.println("i is less than 5"); break; Prepared by: Mr. Rin Ratha Cambodian University for Specialties

4 JAVA Programming ChapterIV case 5: case 6: case 7: case 8: case 9: default: System.out.println("i is less than 10"); break; System.out.println("i is 10 or more"); tmenirkarqøgkat;cuhmkerkamtam case nimyy² rhutdl;cyb break b rhuldl;cugbba b;én switch. kmμvifixagerkamenhcakmrumyy EdlbgðajeGayeXIjc,as;BIkarGnuvtþn_manRbsiT ipabercin. eyigeliyk kmμvifielikmunmksresreligvij duecñheyiggacsegátbikarerbiva³ //an improved version of the season program. class ImprovedSeason{ int month = 4; String season; switch ( month ){ case 12: case 1: case 2: season = "winter"; break; case 3: case 4: case 5: season = "spring"; break; case 6: case 7: case 8: season = "summer"; break; case 9: case 10: case 11: season = "autumn"; break; default: season = "bogus month"; System.out.println("April is in the " + season + "."); eyiggacerbi switch CaEpñkénlMdab;Xøarbs; switch enaxagerka)an. lkçn³enhehafa switch myyenakñúg switch myyetot (nested switch). edayxøa switch kmnt;nuv block erogxøün efviegayvaminman karb:htgáickña rvagtmélefrrbs; case ena switch xagkñúg ehiynig switch xagerka. ]TahrN_ sresrxøa xagerkamenhbitcartwmrtuv³ Prepared by: Mr. Rin Rath Cambodian University for Specialties

5 JAVA Programming ChapterIV switch ( count ){ case 1: case 2: switch ( target ){ case 0:.. case 1: System.out.println ( target is zero ); break; System.out.println ( target is one ); break; 2> XøaRbePT Iteration én Java(Iteration statement): XøaRbePT Iteration enakñúg Java KW for, while nig do-while. XøaTaMgenHbegáIteLIgnUvGVIEdleyIg ehacatuetafa dmenirrgvil (loop). 2>1 dmenirrgvil while (While loop statement) dmenirrgvil while KWCaXøadMenIrbgVilsMxan;bMputrbs; Java. varbrbitþdedl²nuvxøamyy b block myy enaebledlkensamlkçnðbit. enhcatmrg;rbs;va³ while ( condition ){ //body of loop enakñúgenah condition GacCakenSam boolean NamYy. tyéntmenirrgvil nwgrbtibtþirhut ebikensamlkçnð Bit. enaebledl condition minbit enahtmenirepþógpþat; nwgqøgetabnþat;bnþab;én code EdlenACab;nwg tmenir rgvil. ebimanxøaetmyyb:uenñah enaerkamlkçnðedlrtuvepþógpþat;dedl²enah ekmincam)ac;erbisbaøa { et. ]TahrN_enHCargVil while Edlrab;elxfyBI 10 mk ehiye)ahecjnuvbakü tick cmnyn 10 bnþat;. //demonstrate the while loop class WhileLoop{ int n = 10; while ( n > 0 ){ System.out.println("tick " + n); n--; edaysaret while rgvaytmélkñúgkensamlkçnðenaxagelitmenirrgvil tyéntmenirrgvil nwgmin RbtibtþieLIy RbsinebIlkçNÐminBit enaeblcab;epþim. ]TahrN_ code enaxagerkamenh karerbi println() minrbtibtþital;etesah. Prepared by: Mr. Rin Ratha Cambodian University for Specialties

6 JAVA Programming ChapterIV int a = 10, b = 20; while ( a > b ) System.out.println( This will not be displayed ); tyrbs; while b tmenirrgvilepsgetotrbs; Java GacsßitenATeT. enhmkbivacaxøatet CaXøaEdlmanEtsBaØa ; b:uenñah EdlCaXøaRtwmRtUv enakñúgpasa Java. ]TahrN_ cursegátkmμvifixag erkam³ //The target of a loop can be empty class NoBody{ public sattic void main(string Args[]){ int i, j; i= 100; j= 200; while ( ++i < --j ); System.out.println("Midpoint is " + i); 2>2 dmenirrgvil do-while (Do-While loop statement) dmenirrgvil do-while Canic CakalRbtibtþikarkñúgtYrbs;va ya:gticmþg BIeRBaHkenSamlkçNÐ rbs;va enaxagerkaméndmenirrgvil. TMrg;TUeTArbs;vaKW³ do { //body of loop while ( condition ); enakñúgdmenirrgvil do-while Rbtibtþikarmþg² KWdMbUgtYrbs;va rycehiyetibrgvaytmélkensamlkçnð. ebisincakensamlkçnðenah Bit enahdmenirrgvilkwrbtibtþidmenirkarsarcafμimþgetot. pþúyetavij dmenirkarrtuv bba b;. RKb;dMenIrrgVilTaMgGs;rbs; Java, condition RtUvEtCakenSam boolean. kmμvifixagerkamenh Cakmμ vifielikmunedlegaylt plca tick cmnyn 10 dg EtkñúgeBlenHeyIgykvamkeRbICamYyXøa do-while vij mþg. vaegaylt plduckñanwgelikmunedr³ //Demonstrate the do-while loop class DoWhile{ int n = 10; do{ System.out.println("tick " + n); n--; while ( n > 0 ); Prepared by: Mr. Rin Ratha Cambodian University for Specialties

7 JAVA Programming ChapterIV 2>3 dmenirrgvil for (for loop statement) dmenirrgvil for KWCarcnasm<½n myymangnupabxøamg nig manlkçn³bt;ebn. enhcatmrg;tueta rbs; for³ for ( initialization; condition; iteration ){ body; enhcakmμvifierbidmenirrgvil for³ //Demonstrate the for loop class ForTick{ int n; for ( n =10 ; n > 0 ; n-- ){ System.out.println("tick " + n); 2>4 karrbkasgbaøatþienakñúgdmenirrgvil for (Declaring a variable in a for loop) GBaØatþiEdlepÞógpÞat;dMenIrrgVil for KWRtUvkarsMrab;EteKalbMNgénXøa for b:uenñah ehiymin GaceRbIenAkEnøgepSgeTot)aneLIy. enakñúgkrnienh vagacegayeyigrbkasgbaøatþienaxagkñúg for Epñk kmnt;tméldmbugrbs; for. ]TahrN_xageRkamenH CakmμviFIelIkmunEdl)anelIkeLIg duecñhgbaøatþiepþógpþat; dmenirrgvil n nwgrtuvrbkascarbept int ducenakñúgxøa for Edr. //Demonstrate a loop control variable inside for loop class VarLoop{ for ( int n =10 ; n > 0 ; n-- ){ System.out.println("tick " + n); kalnaeyigrbkasgbaøatþimyyenakñúgdmenirrgvil for eyigrtuvdwgfa vamancmnucsmxan;myy KW TMhMén GBaØatþienaHbBa b; enaeblxøa for bba b;edr. enhmann½yfa TMhMrbs;GBaØatþi RtUv)ankMritedayXøa for. kalnagbaøatþiepþógpþat;dmenirrgvil minrtuvkarenakenøgepsgetoenah GñksresrkmμviFIRbkasva ena kñúg for. ]TahrN_xageRkamenH CakmμviFItUcmYy EdlepÞógpÞat;cMnYnbzm. curkt;smkal;fa GBaØatþiepÞógpÞat; dmenirrgvil i RtUvRbkasenAkñúg for erbahvaminrtuvkarerbienakenøgepsgetot. Prepared by: Mr. Rin Ratha Cambodian University for Specialties

8 JAVA Programming ChapterIV //Test for primes. class FindPrime{ int num; boolean isprime = true; num = 14; for ( int i =2; i < num / 2; i++ ){ if ( num % i == 0 ){ isprime = false; break; if ( isprime ) System.out.println("Prime"); else System.out.println("Not Prime"); 2>5 karerbisbaøaek,ós (Using comma) edim,iegaygbaøatþibir b ercinepþógpþat;dmenirrgvil for, Java GaceGayeyIg bba ÚlXøaeRcIn enartg;titamgkmnt;tméldmbug nig TItaMgeFVIskμPaBdEdl²rbs; for. XøamYyenAdac;BIXøamYyeTot edaysbaøa ek,ós. tamry³karerbisbaøaek,ós dmenirrgvil for elikmun GaceGayeyIgsresr code manrbsit i PaBCag duc)anbgðajxagerkamenh³ //Using the comma class Comma{ public static void main(string Args[])[ int a, b; for ( a =1, b =4; a < b; a++, b--){ System.out.println("a = " + a); System.out.println("b = " + b); 2>6 dmenirrgvilmyyenakñúgdmenirrgvilmyyetot (for in for) duckñúgpasad¾étetotedr Java GaceGaydMenIrrgVil sßitkñúgdmenirrgvilmyyeto. xagerkamenh CakmμviFImYy erbi for myyenakñúg for myyetot. Prepared by: Mr. Rin Ratha Cambodian University for Specialties

9 JAVA Programming ChapterIV //loop may be nested class Nested{ int i, j; for ( i = 0 ; i < 10 ; i++ ){ for ( j = i ; j < 10 ; j++ ) System.out.println("."); System.out.println(); 3> XøaRbePT Jump(Jump statement): Java pþl;nuvxøarbept Jump cmnynbikw³ break, continue nig return. 3>1 karerbi break (Using break) enakñúg Java Xøa break mankarerbi 3 ya:g. TImYy duceyig)andwgehiyfa vaerbismrab; bba b; lmdab;enakñúgxøa switch. TIBIr vagacerbismrab;cakecjbidmenirrgvil. TIbI vartu)anerbicatmrg; goto. enaebl enh eyignwgbnül;bikarerbir)as;xøatamgbircugerkayenh. 3>2 karerbi break smrab;cakecjbidmenirrgvil(using break to break a loop) tamry³karerbixøa break eyiggacbgçmegayvabba b;pøam² nuvdmenirkarbgvil)an edayrmlg kensamlkçnð nig code EdlenAsl;kñúgtYén loo. kalnaxøa break myy CYbRbT³enAkñúg loop dmenirrbs; loop RtUv)anbBa b; ehiykmμvifiepþógpþat;nwgcab;epþimenaxøabnþab;. xagerkamca]tahrn_³ //Using break to exit a loop class BreakLoop{ for ( int i = 0; i < 100 ; i++ ) { if ( i == 10 ) break; //terminate loop if i = 10 System.out.println("i: " + i); System.out.println("Loop completed"); Xøa break GaceRbICamYyXøa loop rbs; Java. ]TahrN_xageRkamenHCakmμviFIelIkmunEdl)an sresrbgðajbikarerbidmenirrgvil while. lt plénkmμvifienh k¾ducetanwgkmμvifielikmunedr³ Prepared by: Mr. Rin Ratha Cambodian University for Specialties

10 JAVA Programming ChapterIV //Using break to exit a while loop class BreakLoop2{ int i = 0; while ( i < 100 ) { if ( i == 100 ) break; System.ou.println("i: " + i ); i++; System.out.println("Loop complete"); kalnaerbienakñúgdmenirrgvilercincan;enah Xøa break nwggaccakecjetdmenirrgvilnaedlenakñúg bmput. ]TahrN_³ //Using break with nested loop class BreakLoop3{ for ( int i = 0; i < 3 ; i++ ){ System.out.println("Pass i " + i + ":" ); for ( int j = 0; j < 100 ; j++ ){ if ( j == 10 ) break; System.out.println( j + " " ); System.out.println(); System.out.println("Loop complete"); 3>3 karerbi break ducnwgtmrg; goto(using break as a goto) Xøa break GaceRbIedayxøÜnva edim,ipþl;nuvtmrg; goto. TMrg;TUeTAénXøa break )anbgðajduc xagerkam³ break label; kñúgenah label KWCaeQμaHénsBaØasMKal; EdleRbIsMrab;sMKal; block én code. enaebltmrg;én break enh Rbtibtþikar enahkarepþógpþat;kwsmedaetarkeqμah block én code. Xøa break EdlmaneQμaHRtUvdakenAkñúg block én code. enhmann½yfa eyiggacerbixøa break EdlmaneQμaHsMrab;cakecjBIsMnuM block. b:uenþeyig mingacerbixøa break edim,irk block én code EdlminmanGmXøa break enaheliy. edim,idak;eqμahegay block myy eyigdak;eqμahsbaøasmkal;enaxagedim block nig sbaøa : enabierkay. kmμvifixagerkamenh bgðajbi block bican;edl block nimyy² maneqμaherog²xøün. Xøa break efviegaykarrbtibtþielatetamux hystibba b;én block EdlmaneQμaH second edayrmlgxøa println() BIr. Prepared by: Mr. Rin Ratha Cambodian University for Specialties

11 JAVA Programming ChapterIV //Using a break as a civilized form of goto class Break{ boolean t = true; first: { second: { third: { System.out.println("Before the break."); if ( t ) break second; System.out.println("This wont execute"); System.out.println("This wont execute"); System.out.println("This is after second block"); karerbixøa break CamYyeQμaHsBaØasMKal;eRcInCageKenaH KW edim,icakecjbidmenirrgvilmyy enakñúg dmenirrgvilmyyetot. cursegátkmμvifixagerkamenh³ //Using break to exit from nested loop class BreakLoop4{ public static void main(string Ags[]){ outer: for ( int i = 0 ; i < 3 ; i++ ){ System.out.println("Pass " + i ); for ( int j = 0 ; j < 100 ; j++ ){ if ( j == 10 ) break outer; \\exit both loops System.out.println( j + " "); System.out.pirntln("This will not print"); System.out.println("Loops complete"); duceyig)anexijrsab;ehiyfa enaebldmenirrgvilxagkñúg bmebkecjetakan;dmenirrgvilxagerkaenah dmenirtamgbirrtuv)anbba b;. RtUvcaMTukfa eyigmingacbmebkecjetakan;eqμahsbaøanamyy Edlmin)ankMnt; smrab; block enaheliy. xtahrn_xagerkamenh minrtwmrtuv ehiyminefvikarbmebkecjeliy³ class BreakErr{ one: for ( int i = 0 ; i < 3 ; i++ ){ System.out.println("Pass " + i); for ( int j = 0 ; j < 100 ; j++ ){ if ( j == 10 ) break one; //Wrong System.out.println( j + " " ); Prepared by: Mr. Rin Rtha Cambodian University for Specialties

12 JAVA Programming ChapterIV 4> karerbi Continue(Using a Continue statement): CYnkalvamanRbeyaCn_Edr kñúgkarbgçmegayqab;efviskmμpabdedl² rbs;dmenirrgvil. )ann½yfa eyigcg;bnþdmenirkarrgvil b:uenþbbaäb;dmenirkar code EdlenAesssl; kñúgtyrbs;va cmebahkarefviskmμpab dedl²enh. lkçn³enhkwca goto EdlrMlgtYéndMenIrrgVil etakan;cugerkayéndmenirrgvil. Xøa continue efiv skmμpabebbenh. enhcakmru EdleRbI continue bnþalegaybircmnyn e)ahenaelibnþat;nimyy². //Demonstrate Continue class Continue{ for ( int i = 0 ; i < 10 ; i++ ){ System.out.println( i + " " ); if ( i % 2 == 0 ) continue; System.out.pirntln(" "); duckñanwg break Edr continue GackMnt;nUvsBaØasMKal;mYy edim,ir)ab;nuvdmenirrgvilnaedlrtuv bnþskmμpab. enhcakmμvifimyy EdleRbI continue edim,ie)ahecjnuvtaragmyy ragrtiekanbi 0 dl; 9. //Using continue with label class ContinueLabel{ outer: for ( int i = 0 ; i < 10 ; i++ ){ for ( int j = 0 ; j < 10 ; j++ ){ if ( j > i ){ System.out.println(); continue outer; System.out.println( " " + (i * j) ); System.out.println(); 5> karerbi return(using a return statement): Xøa return RtUv)aneRbIsMrab;eGaytMélBI method myyedayc,as;las;. )ann½yfa vaepþógpþat; edim,ibenþretaegay GñkehA method enah. vartuv)ancat;culcaxøarbept Jump. enaeblnak¾edayenakñúg method myy/ Xøa return GaceRbIsMrab;eFVIeGaykarRbtibtþi EbkecjeTArk GñkehA method enah. duecñh Xøa return bba b; method Pøam² eblvartuv)andmenirkarenakñúg method enah. ]TahrN_xageRkamenHbgðajBIcMnucTaMgenH. kñúgenh return efviegaykarrbtibtþiviletarkrbb½n dmenirkar rbs; Java eblvaeha main. Prepared by: Mr. Rin Ratha Cambodian University for Specialties

13 JAVA Programming ChapterIV //Demonstrate return class Return{ boolean t = true; System.out.println("Before the return"); if ( t ) return; // return to caller System.out.println("This wont execute"); 5 Prepared by: Mr. Rin Ratha Cambodian University for Specialties