App Crashes When Textfield Is Empty

I have tried too many things but after pressing calculate(hesapla) button app crashes everytime. For example: if (vize1.getText().toString().equals('') || fina1.getText().toString

Solution 1:

that's because you want to convert empty string to int. here:

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int v1 = Integer.parseInt(vize1.getText().toString());
        int f1 = Integer.parseInt(fina1.getText().toString());
        int s1 = Integer.parseInt(sort1.getText().toString());

Do this instead for all like:

int v1 = "".equals(vize1.getText().toString()) ? 0 : Integer.parseInt(vize1.getText().toString());

Solution 2:

vize1.getText().toString().equals("") 

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change it to "".equals(vize1.getText().toString())

(apply this to rest of your conditions in if statement)

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in your way if vize1 is null for any reason (maybe has not been declared yet) compiler will throw a nullPointException and crash the app.

Solution 3:

Use the isEmpty() method to test the condition. It uses less code and is more clear about your intentions.