I wrote trivia math application. It is start normally but after 10-20 question i got the mesage “the application has stopped unexpectedly”.
This is the code. I know it is long but maybe you can help
package com.example.learn2;
public class Learn extends Activity {
private Button option_1;
private Button option_2;
private Button option_3;
private Button option_4;
private Button next;
private Button question;
private LinearLayout layout1;
private int[] arrayOf4Cell;
private TextView textScore;
private LinearLayout.LayoutParams params;
private int score=0;
///////////////////
private String xString;
private String yString;
private String ques;
private String correctAnswerTHE_ANSWERString;
private String a;
private String b;
private String c;
private String d;
/////////////////
private Random r;
private Random theQuestion;
private Random oneTOfour;
//////////////
private int correctAnswer;
private int correctAnswerTHE_ANSWER;
private int x;
private int y;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
r= new Random();
theQuestion= new Random();
oneTOfour= new Random();
option_1= new Button(this);
option_2= new Button(this);
option_3= new Button(this);
option_4= new Button(this);
question= new Button(this);
next= new Button(this);
next.setText("שאלה הבאה");
params = new LinearLayout.LayoutParams(
500, LayoutParams.WRAP_CONTENT);
textScore= new TextView(this);
arrayOf4Cell= new int[4];
layout1 = new LinearLayout(this);
option_1.setTextSize(10);
option_2.setTextSize(10);
option_3.setTextSize(10);
option_4.setTextSize(10);
question.setWidth(10);
next.setTextSize(20);
next.setGravity(Gravity.RIGHT);
option_1.setGravity(Gravity.CENTER);
option_2.setGravity(Gravity.CENTER);
option_3.setGravity(Gravity.CENTER);
option_4.setGravity(Gravity.CENTER);
question.setGravity((Gravity.CENTER));
question.setTextSize(20);
question.setBackgroundColor(Color.CYAN);
String scoreString=Integer.toString(score);
textScore.setText(scoreString);
////////////////listener for each button
option_1.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
String text=(String) option_1.getText();
if(text.equals(correctAnswerTHE_ANSWERString)){
Toast.makeText(Learn.this,"נכון!!", Toast.LENGTH_LONG).show();
score++;
String scoreString=Integer.toString(score);
textScore.setText(scoreString);
createAllLauout2();
}
else{
Toast.makeText(Learn.this,"טעות. נסה שוב.", Toast.LENGTH_LONG).show();
score--;
String scoreString=Integer.toString(score);
textScore.setText(scoreString);
}
}
});
option_2.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
String text=(String) option_2.getText();
if(text.equals(correctAnswerTHE_ANSWERString)){
Toast.makeText(Learn.this,"נכון!!", Toast.LENGTH_LONG).show();
score++;
String scoreString=Integer.toString(score);
textScore.setText(scoreString);
createAllLauout2();
}
else{
Toast.makeText(Learn.this,"טעות. נסה שוב.", Toast.LENGTH_LONG).show();
score--;
String scoreString=Integer.toString(score);
textScore.setText(scoreString);
}
}
});
option_3.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
String text=(String) option_3.getText();
if(text.equals(correctAnswerTHE_ANSWERString)){
Toast.makeText(Learn.this,"נכון!!", Toast.LENGTH_LONG).show();
score++;
String scoreString=Integer.toString(score);
textScore.setText(scoreString);
createAllLauout2();
}
else{
Toast.makeText(Learn.this,"טעות. נסה שוב.", Toast.LENGTH_LONG).show();
score--;
String scoreString=Integer.toString(score);
textScore.setText(scoreString);
}
}
});
option_4.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
String text=(String) option_4.getText();
if(text.equals(correctAnswerTHE_ANSWERString)){
Toast.makeText(Learn.this,"נכון!!", Toast.LENGTH_LONG).show();
score++;
String scoreString=Integer.toString(score);
textScore.setText(scoreString);
createAllLauout2();
}
else{
Toast.makeText(Learn.this,"טעות. נסה שוב.", Toast.LENGTH_LONG).show();
score--;
String scoreString=Integer.toString(score);
textScore.setText(scoreString);
}
}
});
layout1.setGravity(Gravity.CENTER_VERTICAL);
layout1.setOrientation(LinearLayout.VERTICAL);
layout1.setBackgroundColor(Color.argb(5, 102, 102, 204));
layout1.addView(textScore);
layout1.addView(question);
layout1.addView( option_1);
layout1.addView(option_2);
layout1.addView(option_3);
layout1.addView(option_4);
layout1.addView(next);
createAllLauout2();
setContentView(layout1);
next.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
createAllLauout2();
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_learn, menu);
return true;
}
public void createAllLauout2(){
correctAnswer=oneTOfour.nextInt(4);
correctAnswerTHE_ANSWER = r.nextInt(10);
correctAnswerTHE_ANSWERString=Integer.toString(correctAnswerTHE_ANSWER);
x=theQuestion.nextInt(correctAnswerTHE_ANSWER); // x in x+y
y=correctAnswerTHE_ANSWER-x; //y in x+y
xString=Integer.toString(x);
yString=Integer.toString(y);
ques=xString + "+" + yString;
question.setText(ques);
arrayOf4Cell[0]=correctAnswerTHE_ANSWER+3;
arrayOf4Cell[1]=correctAnswerTHE_ANSWER*6;
arrayOf4Cell[2]=correctAnswerTHE_ANSWER*2+4;
arrayOf4Cell[3]=correctAnswerTHE_ANSWER*5+1;
arrayOf4Cell[correctAnswer]=correctAnswerTHE_ANSWER; //one of the cell get the right answer
a=Integer.toString(arrayOf4Cell[0]);
b=Integer.toString(arrayOf4Cell[1]);
c=Integer.toString(arrayOf4Cell[2]);
d=Integer.toString(arrayOf4Cell[3]);
option_1.setText(a);
option_2.setText(b);
option_3.setText(c);
option_4.setText(d);
layout1.updateViewLayout(question, params);
layout1.updateViewLayout(option_1, params);
layout1.updateViewLayout(option_2, params);
layout1.updateViewLayout(option_3, params);
layout1.updateViewLayout(option_4, params);
layout1.updateViewLayout(textScore, params);
}
}
This is logcat:
09-27 16:59:06.142: D/AndroidRuntime(2314): Shutting down VM
09-27 16:59:06.152: W/dalvikvm(2314): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
09-27 16:59:06.152: E/AndroidRuntime(2314): FATAL EXCEPTION: main
09-27 16:59:06.152: E/AndroidRuntime(2314): java.lang.IllegalArgumentException
09-27 16:59:06.152: E/AndroidRuntime(2314): at java.util.Random.nextInt(Random.java:225)
09-27 16:59:06.152: E/AndroidRuntime(2314): at com.example.learn2.Learn.createAllLauout2(Learn.java:246)
09-27 16:59:06.152: E/AndroidRuntime(2314): at com.example.learn2.Learn$4.onClick(Learn.java:183)
09-27 16:59:06.152: E/AndroidRuntime(2314): at android.view.View.performClick(View.java:2408)
09-27 16:59:06.152: E/AndroidRuntime(2314): at android.view.View$PerformClick.run(View.java:8816)
09-27 16:59:06.152: E/AndroidRuntime(2314): at android.os.Handler.handleCallback(Handler.java:587)
09-27 16:59:06.152: E/AndroidRuntime(2314): at android.os.Handler.dispatchMessage(Handler.java:92)
09-27 16:59:06.152: E/AndroidRuntime(2314): at android.os.Looper.loop(Looper.java:123)
09-27 16:59:06.152: E/AndroidRuntime(2314): at android.app.ActivityThread.main(ActivityThread.java:4627)
09-27 16:59:06.152: E/AndroidRuntime(2314): at java.lang.reflect.Method.invokeNative(Native Method)
09-27 16:59:06.152: E/AndroidRuntime(2314): at java.lang.reflect.Method.invoke(Method.java:521)
09-27 16:59:06.152: E/AndroidRuntime(2314): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
09-27 16:59:06.152: E/AndroidRuntime(2314): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
09-27 16:59:06.152: E/AndroidRuntime(2314): at dalvik.system.NativeStart.main(Native Method)
The problem is here:
when
correctAnswerTHE_ANSWERis0.You cannot call
nextInt(0). Check out Random#nextInt()`.A quick fix is to check:
But I’m not certain what you are doing so hopefully you will find a better solution.