We Keep Coding

Why does StringBuilder result in a longer runtime in this program?

I read in another thread that StringBuilder is superior to String Concatenation, especially within loops. However, I solved the problem in two different ways, and the StringBuilder method took nearly double the runtime - The logic is otherwise the same, so why might this be?
class Solution {
public int reverse(int x) {
boolean isNeg = false;
if(x < 0){
x *= -1;
isNeg = true;
}
ArrayList <Character> arrlist = new ArrayList<>();
String reverse = "";
StringBuilder sbdr = new StringBuilder();
String s = Integer.toString(x);
for(int i = 0; i < s.length(); i++) arrlist.add(s.charAt(i));
while(arrlist.get(arrlist.size()-1) == '0' && arrlist.size() > 1) {
arrlist.remove(arrlist.size()-1);
}
for(int i = arrlist.size()-1; i >= 0; i--) sbdr.append(arrlist.get(i));
try {
if(isNeg) return Integer.valueOf(sbdr.toString())*-1;
return Integer.valueOf(sbdr.toString());
} catch (Exception e){
return 0;
}
}
}
class Solution {
public int reverse(int x) {
boolean isNeg = false;
if(x < 0){
x *= -1;
isNeg = true;
}
ArrayList <Character> arrlist = new ArrayList<>();
String reverse = "";
String s = Integer.toString(x);
for(int i = 0; i < s.length(); i++) arrlist.add(s.charAt(i));
while(arrlist.get(arrlist.size()-1) == '0' && arrlist.size() > 1) {
arrlist.remove(arrlist.size()-1);
}
for(int i = arrlist.size()-1; i >= 0; i--) {
reverse += Character.toString(arrlist.get(i));
}
try {
if(isNeg) return Integer.valueOf(reverse)*-1;
else return Integer.valueOf(reverse);
} catch (Exception e){
return 0;
}
}
}

Created a class to print an array of generic objects but I get no output?

Basically it's a array list implementation and I need to time how long it takes to add elements to it, along with other features. I compiled it though and there's no output and I can't find the problem. I instantiate an array of objects in the class then defined a method add(E e) to add an element E using basic assignment. Then the ListDriver should populate the array using the add() method and print it, but again, no output.
public class MyArrayList<E> {
public Object array[];
public int size = 0;
private static final int INITIAL_CAPACITY = 100;
public MyArrayList() {
array = new Object[INITIAL_CAPACITY];
this.size = 0;
}
private boolean arrayFull() {
if (size == array.length)
return true;
else
return false;
}
private boolean remove(Object o) {
for (int i = 0; i < size; i++) {
if (array[i].getClass() == o.getClass()) {
remove(i);
return true;
}
}
return false;
}
private void resize(int i) {
if (i == 0) {
Object[] temp = new Object[array.length*2];
for (int j = 0; j < size; j++) {
temp[j] = array[j];
}
this.array = temp;
}
if (i == 1) {
Object[] temp = new Object[array.length/2];
for (int j = 0; j < size; j++) {
temp[j] = array[j];
}
this.array = temp;
}
}
public void add(E e) {
if (!arrayFull()) {
array[size] = e;
size++;
}
else if (arrayFull()) {
resize(0);
add(e);
}
}
public int size() {
return size;
}
private void clear() {
array = null;
}
private Object remove(int index) {
if (halfFull()) {
resize(1);
}
Object temp = array[index];
for (int i = index; i < size; i++) {
array[i] = array[i+1];
}
size--;
return temp;
}
private boolean halfFull() {
if (size < (array.length/4)) {
return true;
}
else return false;
}
public void add(int index, E element) {
if (!arrayFull()) {
for (int i = size-1 ; i >= index ; i--) {
array[i] = array[i+1];
}
array[index] = element;
size++;
}
else {
resize(0);
add(index, element);
}
}
public String toString() {
String list = new String();
for (int i = 0; i < size; i++) {
list += " " + array[i];
}
return list;
}
public static void main(String[] args) {
MyArrayList temp = new MyArrayList();
System.out.println(temp.size);
}
}
And the driver
public class ListTester {
public static void main(String[] args) {
int n = 100;
MyArrayList arrayList = new MyArrayList();
int[] array = new int[n];
for (int i = 0; i < array.length; i++) {
array[i] = (int)Math.random() *2*n +1;
}
long startTime = System.nanoTime();
for (int i = 0; i < arrayList.size(); i++) {
arrayList.add(array[i]);
}
long endTime = System.nanoTime();
long duration = endTime - startTime;
System.out.println(arrayList);
System.out.println(duration);
}
}

StringBuilder delete method cannot delete all '0' in for loop

I hava a StringBuilder Object named ans which start with lots of '0'. I try to delete all the '0' from the start of the ans until I meet a non '0' charactar.
What confuse me is the for i loop didn't finish his job. I have to make a second for i loop to clear all the 0 in the beginning.
Here is my Code.
public class No402 {
public static void main(String[] args) {
System.out.println(new No402().removeKdigits("427678546157908202929448318407149433598941870479484500373368094012640922988944903397231702353051296772670609336191726825787647245280246494510751316791097772635916484567294854648398773200614610692439749334983719345750125285558273389537247808616627840348391541780405632498175550670814483322235884114191684425539700201183703587949597798648197144029680034703650447978815274453409769451938181194670236539615076076724801152265796791950839841075506496208242283345315438812485232707288458830113475578067141259885957507974459034601870691029238278145117967672455748598562454335352022138663578650018932794815560444310763231019675787261694371678668644339854958907821773372271852187220032032017945244736581208187579068580185227767156390103505841791926185740325681181186094285141493501371797997985093633429331681417037952779606099025781939653539667327585223193265104760031416279764954711946476511917659406238018486507799968619917168011928683817145926711572133853584543722586782861850386612518980411994554848814979739368861292867806867477023542666766491330473452688039707721365747787240596809108898467010318334680687019792696629839565024851680339466097701378426511460592730828365060773384536771501978655900891991610586513361508749654736996060516167501074422771971789366881416910565182663861728132945113466551823237774192421468035396298083950499656995352722769028176149929176129270259795714360564181789491402258317140100263975814386471443888504481437823849930509081817821217842949224442188241777980524546168024420433856730945107002523873515905052413576563963761705708386370684295123300655474726135777514101525139157141660578834089922712818235921723336548872233862325519757636038517100204717301611841806408125342937951489730656480403209360817193216570158732512524381799352135220367775084052315596359332185881469685785759643790379007388205622217833707637182705482719421608792833467331390627216761585223615336687044623982580102748517565040221706925579685343543433009769255586626565520212255360522361667336713708104934788577796561605570331306991967305968238358669423834060143243437837775392376777924519897791910058008216120575271730691560477468863142648888869200219888646983369733759492212070871512937926423826675208524061571339017204141805776136878655729439344699075025582325795053715422074000251722784817154432916934019414677632486724448910297784648508509989104518665322517602655737296038028919796811999411990582627532510512470388148984501921600690498245678513418659488192884672038751754737701342001976844578264865187098814701028520932014579657202152130584876731914095428618962111105699155557888539748410740763666856050588875362602217123514830967968296887038058927978692977960033347709944437947894602596394368654378129102419614453823575240338123122247834358097482528154365054702484821681725423667772577336535604562191507529211126152260170715256336436732642411224638751755830777617805733331013931482237642951105302308336467179236307457388120864127366714063433682982521560321184745430570996517984127401390131041234803476082369518236013362475086748897894944837946280014253441657837884290497302913267754550157853275778653770643975667949187398314140797876931982481406371131255655953059982825807216762616344985662379666143189413977342680154255688907404253127782382526628767469541562535190774117320180858461198897338392684534129689078589436930895977385457740728688710228393814469380755500395367428641990009083899255546917778501801615243321300732438819702863842491501369876330552080763882689583443289191456202883115373878537481769070534345339487448768652397897072067270546991518766905890231276937848590051268672451449905411445025714751792817425905371055159173767061674730112185822983938796512005449307370959938924114252201152924555120466405871744781491655943770916260603103914052438385771427993705039652447037651387566275180237439471198029869865322525461164779510272313071316281030421040396294999195727355293454393355497271426647362022930264843444410506305670272534713691035602664829458794412090047701646750201154767836534661740127416617239935006553696971096260102693800760739330158647617041766117030721391467475970038655210226421042284196198439271082602380845703971387087401814743471632415224467806206033924036876038880765536790459548338714608707551091322717386914597468513209267971136254411430104017581870733925000780611661861497274096760206127314774774968626483249931563903125145099781823940050491763256564829253143343088460200464400006390944981948883242422745433557725035229145605525982239471184637428415157236778717495038740069242295683541064047888003373477407269609038056842212638374869507872489116470722448681816169580297691905943680441106791796396459808602015974302677774596553728719933524655181171746711337423848855311272396045201051237272308499116803264436840003404461479378736677672276248424413902969009951795200806416102927228501194648365803250904713237362258902949801429885956943940730532158950133461018349339812475473726972464370080310253349268708055345896432886263126744425495156968409721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628726377006207603592185", 8222));
}
public String removeKdigits(String num, int k) {
if (num.length() == k) {
return "0";
}
Deque<Character> deq = new LinkedList<>();
int howmany2cut = k;
char[] numsChar = num.toCharArray();
int finalIndx = 0;
for (int i = 0; i < numsChar.length && k > 0; i++) {
if (deq.isEmpty()) {
deq.add(numsChar[i]);
continue;
}
if (deq.peekLast() <= numsChar[i]) {
deq.add(numsChar[i]);
continue;
}
if (deq.peekLast() > numsChar[i]) {
while (k > 0) {
if (!deq.isEmpty() && (deq.peekLast() > numsChar[i])) {
deq.pollLast();
k--;
} else {
break;
}
}
deq.add(numsChar[i]);
finalIndx = i + 1;
}
}
StringBuilder ans = new StringBuilder();
for (Character n : deq) {
ans.append(n);
}
if (deq.size() < num.length() - k) {
ans.append(num.substring(finalIndx));
}
if (ans.length() > 1) {
for (int i = 0; i < ans.length(); i++) {
if ('0' == ans.charAt(0)) {
ans.delete(0, 1);
} else {
break;
}
}
} else {
return ans.toString();
}
if (ans.length() > 1) {
for (int i = 0; i < ans.length(); i++) {
if ('0' == ans.charAt(0)) {
ans.delete(0, 1);
} else {
break;
}
}
}
if (ans.length() == 0) {
return num.length() - howmany2cut > 0 ? num.substring(0, num.length() - howmany2cut) : "0";
}
if (ans.length() > num.length() - howmany2cut) {
return ans.substring(0, num.length() - howmany2cut);
}
return ans.toString();
}}
here is my debug picture
Please help me , thank you!

The reason why all 0's are not deleting after the first loop is that you are removing elements inside the loop if the first character is zero. Which causing the decrease in ans.length() so due to this the loop is not going up to the full length.
One more thing there is no need for 2 for loops you can manage it with just one loop.
How to fix?
Just store the actual length of ans before beginning the deletion and place it in the loop condition like this
public class No402 {
public static void main(String[] args) {
System.out.println(new No402().removeKdigits("42767854615790820292944831840714943359894187047948450037336809401264092298894490339723170235305129677267060933619172682578764724528024649451075131679109777263591648456729485464839877320061461069243974933498371934575012528555827338953724780861662784034839154178040563249817555067081448332223588411419168442553970020118370358794959779864819714402968003470365044797881527445340976945193818119467023653961507607672480115226579679195083984107550649620824228334531543881248523270728845883011347557806714125988595750797445903460187069102923827814511796767245574859856245433535202213866357865001893279481556044431076323101967578726169437167866864433985495890782177337227185218722003203201794524473658120818757906858018522776715639010350584179192618574032568118118609428514149350137179799798509363342933168141703795277960609902578193965353966732758522319326510476003141627976495471194647651191765940623801848650779996861991716801192868381714592671157213385358454372258678286185038661251898041199455484881497973936886129286780686747702354266676649133047345268803970772136574778724059680910889846701031833468068701979269662983956502485168033946609770137842651146059273082836506077338453677150197865590089199161058651336150874965473699606051616750107442277197178936688141691056518266386172813294511346655182323777419242146803539629808395049965699535272276902817614992917612927025979571436056418178949140225831714010026397581438647144388850448143782384993050908181782121784294922444218824177798052454616802442043385673094510700252387351590505241357656396376170570838637068429512330065547472613577751410152513915714166057883408992271281823592172333654887223386232551975763603851710020471730161184180640812534293795148973065648040320936081719321657015873251252438179935213522036777508405231559635933218588146968578575964379037900738820562221783370763718270548271942160879283346733139062721676158522361533668704462398258010274851756504022170692557968534354343300976925558662656552021225536052236166733671370810493478857779656160557033130699196730596823835866942383406014324343783777539237677792451989779191005800821612057527173069156047746886314264888886920021988864698336973375949221207087151293792642382667520852406157133901720414180577613687865572943934469907502558232579505371542207400025172278481715443291693401941467763248672444891029778464850850998910451866532251760265573729603802891979681199941199058262753251051247038814898450192160069049824567851341865948819288467203875175473770134200197684457826486518709881470102852093201457965720215213058487673191409542861896211110569915555788853974841074076366685605058887536260221712351483096796829688703805892797869297796003334770994443794789460259639436865437812910241961445382357524033812312224783435809748252815436505470248482168172542366777257733653560456219150752921112615226017071525633643673264241122463875175583077761780573333101393148223764295110530230833646717923630745738812086412736671406343368298252156032118474543057099651798412740139013104123480347608236951823601336247508674889789494483794628001425344165783788429049730291326775455015785327577865377064397566794918739831414079787693198248140637113125565595305998282580721676261634498566237966614318941397734268015425568890740425312778238252662876746954156253519077411732018085846119889733839268453412968907858943693089597738545774072868871022839381446938075550039536742864199000908389925554691777850180161524332130073243881970286384249150136987633055208076388268958344328919145620288311537387853748176907053434533948744876865239789707206727054699151876690589023127693784859005126867245144990541144502571475179281742590537105515917376706167473011218582298393879651200544930737095993892411425220115292455512046640587174478149165594377091626060310391405243838577142799370503965244703765138756627518023743947119802986986532252546116477951027231307131628103042104039629499919572735529345439335549727142664736202293026484344441050630567027253471369103560266482945879441209004770164675020115476783653466174012741661723993500655369697109626010269380076073933015864761704176611703072139146747597003865521022642104228419619843927108260238084570397138708740181474347163241522446780620603392403687603888076553679045954833871460870755109132271738691459746851320926797113625441143010401758187073392500078061166186149727409676020612731477477496862648324993156390312514509978182394005049176325656482925314334308846020046440000639094498194888324242274543355772503522914560552598223947118463742841515723677871749503874006924229568354106404788800337347740726960903805684221263837486950787248911647072244868181616958029769190594368044110679179639645980860201597430267777459655372871993352465518117174671133742384885531127239604520105123727230849911680326443684000340446147937873667767227624842441390296900995179520080641610292722850119464836580325090471323736225890294980142988595694394073053215895013346101834933981247547372697246437008031025334926870805534589643288626312674442549515696840972195844322623489776395993997725883102424374473386242230020052319139538725050694563793252575203302986006568926586341522483619750551265949811840701660706687971699572637332236706033725130460780147305930796689592739802762127602300331109088320407488753453562201443009583869340530260133192585867600117793558618622877626140608235883463446585052941889282771610713456594091731994663257672424562807919185250771570978748558016087655314386429181778154999037395977801201222536602668579318195917221851258101758083465833807764504478328133760033685582322103480724065531895932039917203779203156040553746346772387443929520551627122239575483559165994485703508677722865190370481258839816840706093115274279356732858077656941579688491810646089766375954256605013212947107680641700379830628558534532701353225658907237335822869646320919937486195881402477347072922997644748078880017641720321497893274887727279247817230724007001520405446788235407924339589275318658718824019308723325037628135839936194865389246778785484224136240513164802724185350906503263939998152201969404224284851353929162842159002494160461334274924788445418313020719064697643073211899597216839617241323956298475147631936745340993794786362122100021070985418754276295234662670333162104340353095385544657319880579379906274682249802800845859334842970692716308206359497045039047894058089399866389624780981978085896624346900360571598520216940381587071285958497155631482721452214648993874243450874956631856720123296440913509093669827146153180469767433504561046437484524515293979237377991209712765962632838588822180359961992788574139615251950913574644651207439995528858114472995911722528828790960400270676875166161939741700924096377882962772526118510149529098157733017933337496630319171190616687753486928733354625068986857196646261563989044574797981270617089057226390794666311751192327631540192548655459578506043592663616062769069836457346194068474176132510064511610117400341310411426000998578144122817400179584819131405912398612085587124626912794546013764785843274068027858995747888172680971572206968091015445337290861835783980747471461015521311208355915962202714480089884097249709377165451728632422251230084667248727648072440251993269156317610868685295846232492883010588697174635533597605834450249882921427658569868883414799635112078926523707047988262628826843234898036034699263633285219983947947102364186704490860419225940767023498819222899748637736136929299603365634669304329289193002180868079267831256753666692578016598885536576757243005565124272778934460000656133474422706312579704797332965888987321865639934115540341358438065159979966516649509059972742742859883148151328808103859578112480441464277834533174833896376621814776042440697291859846516369392086372254665861285937409320474020680208941413993134675771984152737919309617874095184511004441704637414657377204495521150940370391369816136133983987959653102357045282415379947968251076420098012505820501069271733453309150705588274173445852803861126110689326352001921046066346433959229953549279092972503658190837209557302503876248001129441633640343374507764567392795980560783306587466656895994346821030188171996741604459649768510697714192580042040101750692371398942842500442445462269343139517683266487839338542443169246460653530698650325346136357734184681042975047635944793223022235246268651870018710450581435529607254366048869493833744884331399960456341161524764264081615200455615465925723132075411240169896584999493701334792763601560521725937880035580427191600072833098777060365102978298741740559073275852763938780836609797603716875112885764040607658550533844408290490010802790842002942292935369291644839617793990910895308977723653062881593207714109720695034340437197019621968080117519794848132586742911614980669439330348142456126849768719198483462298008318935405664818315956667907954514033766806239587330742325680711653716183320470951491901907421070418246355033490024779722775524553362711286647617964163847164933401979458666304006708368763218332476561345205255639459643444256743045787508311558394991701816915267581835649555296896252897237006404723594796400109216516930136483261469100739753281302804818082275735965571356243205409672153514152830169411991633125429246600926046750109377245075186063774301024268884824103787866848063266853457600668442319180654169447895010411843408292686118099805402852556814966811008369348597110442872837094072059087232837205291461239853639994518924479438927379348327739109781565914159761167665584025124425923844801188360781762018699315163461229173330894272797116474430040071501881164984840886621509629770804885731934408262630754177569630312231904935609457496213783238786007928894185681679202644961896031520772120429456532334651866707926275039616875628244135012101648429121896413946679889877828086708457516884940565793756567939396973544976573326617620245079002790968407887831523704293463842790307287785628353910524550357149296905848302331279051221613790082068853444332742995671850649946821132877723913186786300652152247618157706125750578092402909964449626211673467131785274416643250628726377006207603592185", 8222));
}
public String removeKdigits(String num, int k) {
if (num.length() == k) {
return "0";
}
Deque<Character> deq = new LinkedList<>();
int howmany2cut = k;
char[] numsChar = num.toCharArray();
int finalIndx = 0;
for (int i = 0; i < numsChar.length && k > 0; i++) {
if (deq.isEmpty()) {
deq.add(numsChar[i]);
continue;
}
if (deq.peekLast() <= numsChar[i]) {
deq.add(numsChar[i]);
continue;
}
if (deq.peekLast() > numsChar[i]) {
while (k > 0) {
if (!deq.isEmpty() && (deq.peekLast() > numsChar[i])) {
deq.pollLast();
k--;
} else {
break;
}
}
deq.add(numsChar[i]);
finalIndx = i + 1;
}
}
StringBuilder ans = new StringBuilder();
for (Character n : deq) {
ans.append(n);
}
if (deq.size() < num.length() - k) {
ans.append(num.substring(finalIndx));
}
int tempLength = ans.length(); //Store length like this
if (ans.length() >= 1) {
for (int i = 0; i < tempLength; i++) { //pass the tempLength as termination condition like this
if ('0' == ans.charAt(0)) {
ans.delete(0, 1);
} else {
break;
}
}
}
if (ans.length() == 0) {
return num.length() - howmany2cut > 0 ? num.substring(0, num.length() - howmany2cut) : "0";
}
if (ans.length() > num.length() - howmany2cut) {
return ans.substring(0, num.length() - howmany2cut);
}
return ans.toString();
}}

Im receiving a String index out of range question for a java program i wrote for my assignment

I would like to apologise in advance if im doing something wrong with the code formatting because this is my second time posting here
I have a java assignment due in a couple of days in which the user enters a string and only the integers are collected from it and placed in the array intArray
Now i think i got the logic right in the code below but when i run it in the main, it asks for the string and the boolean, when i enter both it gives me the error
"Exception in thread "main" java.lang.StringIndexOutOfBoundsException: String index out of range: 115"
This is what i entered for example
"Enter a string and true if you want to skip errors or false if you want to skip errors
sdak23
false"
this is my main:
import java.util.Scanner;
public class MainStringToIntArray {
public static void main(String[] args) {
Scanner intut = new Scanner(System.in);
Scanner input = new Scanner(System.in);
StringToIntArray s1 = new StringToIntArray();
System.out.println("Enter a string and true if you want to skip errors or false if you want to skip errors");
s1.scanStringToIntArray(intut.next(), input.nextBoolean());
}
}
import java.util.Arrays;
import java.util.Scanner;
public class StringToIntArray {
private int[] intArray = new int[10];
public StringToIntArray() {
Arrays.fill(intArray, Integer.MIN_VALUE);
}
public int indexOf(int intToFind) {
int b = 0;
for (int a = 0; a < intArray.length; a++) {
if (intArray[a] == intToFind) {
b = intArray[a];
}
else {
b = -1;
}
}
return b;
}
public int indexOf(String intToFind) {
int b = 0;
for (int a = 0; a < intArray.length; a++) {
if (intArray[a] == Integer.parseInt(intToFind)) {
b = intArray[a];
}
else {
b = -1;
}
}
return b;
}
public boolean contains(int intToFind) {
int a = indexOf(intToFind);
if (a > 0) {
return true;
}
else {
return false;
}
}
public boolean contains(String intToFind) {
int a = indexOf(intToFind);
if (a > 0) {
return true;
}
else {
return false;
}
}
public int get(int index) {
if(index < 0 && index > 10) {
return Integer.MIN_VALUE;
}
else {
return intArray[index];
}
}
public boolean scanStringToIntArray(String s, Boolean skipErrors) {
Boolean result = null;
Scanner input = new Scanner(s);
int l = s.length();
if ((skipErrors)) {
String discard = null;
for (int a = 0; a < l; a++) {
for (int z = 0; z < l; z++) {
if (input.hasNextInt(s.charAt(z))) {
intArray[a] = s.charAt(z);
System.out.println(a);
result = true;
}
else {
discard = discard + s.charAt(z);
}
}
}
}
else {
for (int v = 0; v < l; v++) {
for (int p = 0; p < l; p++) {
if ((input.hasNextInt(s.charAt(p)))) {
intArray[v] = s.charAt(p);
System.out.println(v);
}
else {
System.out.println(v);
result = false;
}
}
}
}
return result;
}
}

The issue is in the get method. It is logically impossible for the index to be both less than 0 and greater than 10; you probably want to use the logical or operator (||). Also, the maximum index of the array is actually 9, as arrays are zero indexed.
public int get(int index) {
if(index < 0 || index > 9) {
return Integer.MIN_VALUE;
}
else {
return intArray[index];
}
}
There are other logical errors in your code as well. All your indexOf methods should be returning the index where the element was first found instead of the element itself and your else branch is always resetting it to -1 each time it is not found.

need help on my tic tac toe demo invalid top level statement

public class TicTacToe
{
private char currentPlayer;
private char[][] board;
public TicTacToe()
{
board = new char [3][3];
currentPlayer = 'x';
startBoard();
}
public void startBoard()
{
for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 3; j++)
{
board[i][j] = '-';
}
}
}
public void makeBoard()
{
System.out.println("---------------");
for (int i = 0; i < 3; i++)
{
System.out.print("| ");
for (int j = 0; j < 3; j++)
{
System.out.print(board[i][j] + " | ");
}
System.out.println();
System.out.println("---------------");
}
}
public boolean fullBoard()
{
boolean full = true;
for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 3; j++)
{
if (board[i][j] == '-')
{
full = false;
}
}
}
return full;
}
public boolean win()
{
return (rowWin() || columnWin() || diagWin());
}
private boolean rowWin()
{
for (int i = 0; i < 3; i++)
{
if (rowColumn(board[i][0], board[i][1], board[i][2]) == true)
{
return true;
}
}
return false;
}
private boolean columnWin()
{
for (int i = 0; i < 3; i++)
{
if (rowColumn(board[0][i], board[1][i], board[2][i]) == true)
{
return true;
}
}
return false;
}
private boolean diagWin()
{
return ((rowColumn(board[0][0], board[1][1], board[2][2]) == true) ||
(rowColumn(board[0][2], board[1][1], board[2][0]) == true));
}
private boolean rowColumn(char rc1, char rc2, char rc3)
{
return ((rc1 != '-') && (rc1 == rc2) && (rc2 == rc3));
}
public void playerChange()
{
if (currentPlayer == 'x')
{
currentPlayer = 'o';
}
else
{
currentPlayer = 'x';
}
}
public boolean placeMark(int row, int column)
{
if ((row >= 0) && (row < 3))
{
if ((column >= 0) && (column < 3))
{
if (board[row][column] == '-')
{
board[row][column] = currentPlayer;
return true;
}
}
}
return false;
}
}
public class TicTacToedemo
{
public static void main(String[] args)
{
TicTacToe demo = new TicTacToe();
demo.makeBoard();
if (demo.win())
System.out.println("Winner! Hooray!");
else if (demo.fullBoard())
System.out.println("Cat Scratch, Draw.");
demo.playerChange();
}
}
I am not sure how to play the game right, every time I input numbers when I run it, I get the error code. What have I done wrong with this? The code can be compiled and runs and displays the board but when I go to put in the place I want the x or the o to go I get the error code " invalid Top level statement "

You have to use the Scanner class to make a player input using import java.util.Scanner then storing the input. After the import it going to look like this:
Scanner sc = new Scanner(System.in);
int input = sc.nextInt();
And you have to manage the sc.nextInt() result, in this example the input variable.