CODEWITHSUNDEEP
javaandroid
Turwaith
Turwaith

Reputation: 67

Java Simple number game App crashes when EditText is empty

I have made a simple Android app, where the app creates a number between 1 and 20 and the user has to guess it. Everything works fine, except one thing: When I let the EditText empty, the App crashes instantly when I press the Button. How can I prevent that? I tried an if-else Argument at the point where the entered Text of the EditText is given to the global created editText Variable editTextGuess, but then the app crashed instantly after launch.

What do I have to Code, that the app does not crash caused by the empty textfield but creates a toast saying "Oops, your Textfield is empty"?

package com.example.randomness;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;

import java.util.Random;

public class MainActivity extends AppCompatActivity {

    //Den EditText und den Integer für die zufällige Zahl global erstellen
    EditText editTextGuess;
    int RandomNumber;

    //Hier einen Void eröffnen, um die zufällige Zahl zu erstellen
    public void generateRandomNumber(){
        Random random = new Random();

        RandomNumber = random.nextInt(20) +1;
    }

    //Erstellen der OnClick Methode für den Button, View view ist wichtig!
    public void guess(View view){
        Log.i("Button clicked", "Worked!");

        int guessValue;
        guessValue = Integer.parseInt(editTextGuess.getText().toString());
        Log.i("Entered Value:", Integer.toString(guessValue));
        Log.i("The random number is:", Integer.toString(RandomNumber));


        String message;

        if(guessValue > RandomNumber){
            message = "Your guessed number is too high!";
        } else if(guessValue < RandomNumber){
            message = "Your guessed number is too low!";
        } else if(guessValue == RandomNumber){
            message = "You were right! Let's play again!";
            generateRandomNumber();
            Log.i("Info", "New random number created");
        } else {
            message = "Something went wrong...";
        }

        Toast.makeText(this, message, Toast.LENGTH_LONG).show();

    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        editTextGuess = findViewById(R.id.editTextRaten);
        generateRandomNumber();

    }
}

Upvotes: 2

Views: 321

Answers (4)

Ratish Bansal
Ratish Bansal

Reputation: 2462

As the issue has already been pointed out by @Yousaf this answer that will help you move forward but would like to add few things to take care in future to help debugging easier: Always try to create multiple statements where you are dereferencing object like

guessValue = Integer.parseInt(editTextGuess.getText().toString());

can be written as

String text=editTextGuess.getText().toString();
guessValue = Integer.parseInt(text);

It will help you know the exact cause of failure.Like you may encounter NumberFormatException if the entered string is not number.

Upvotes: 0

MC Emperor
MC Emperor

Reputation: 23017

It crashes because parseInt() throws a NumberFormatException when it tries to parse an empty string.

How to fix this depends on what you want if the input field is empty.

String value = editTextGuess.getText().toString();
if (!value.isEmpty()) {
    guessValue = Integer.parseInt(value);
    ...
}
else {
    Toast.makeText(this, "Oops, input field is empty", ...);
}

Upvotes: 0

Zankrut Parmar
Zankrut Parmar

Reputation: 1997

Check your edit text string value before assigning it to the variable.

public void guess(View view){
    Log.i("Button clicked", "Worked!");

    int guessValue;
    if(!editTextGuess.getText().toString().equals("")){
        guessValue = Integer.parseInt(editTextGuess.getText().toString());
        Log.i("Entered Value:", Integer.toString(guessValue));
        Log.i("The random number is:", Integer.toString(RandomNumber));


        String message;

        if(guessValue > RandomNumber){
            message = "Your guessed number is too high!";
        } else if(guessValue < RandomNumber){
            message = "Your guessed number is too low!";
        } else if(guessValue == RandomNumber){
            message = "You were right! Let's play again!";
            generateRandomNumber();
            Log.i("Info", "New random number created");
        } else {
            message = "Something went wrong...";
        }

        Toast.makeText(this, message, Toast.LENGTH_LONG).show();
    }  else {
        Toast.makeText(this, "Oops, your Textfield is empty", Toast.LENGTH_LONG).show();
    }

}

Upvotes: 0

Yousaf
Yousaf

Reputation: 29314

Before you try to use text from EditText, check if it contains any text or not. If it does, read the text otherwise display a toast

String text = editTextGuess.getText().toString().trim();

if(text.length == 0) {
  // show toast
} else {
  // use text from  editTextGuess
}

Upvotes: 2

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