Question

well the calculation in my app goes like this..

have a edittext box where the input(number) from the user is parsed to int as nos.

based on the input two other sets of edittext box appears.

if nos is 3 the 3 edittext from arrayOfEditText and 3 edittext from arrayOfEditText1 appears..
and the value entered in those sets of edittext are used for calculation.

the incomplete java code is below..

    calculate.setOnClickListener(new View.OnClickListener() {
                            @Override public void onClick(View v) {
                    // TODO Auto-generated method stub
                    chk();          
}       
});     
}   
public void chk()   {   
            EditText[] arrayOfEditText = new EditText[11];
            arrayOfEditText[1] = ((EditText)findViewById(R.id.EditText01));
            arrayOfEditText[2] = ((EditText)findViewById(R.id.EditText02));
            arrayOfEditText[3] = ((EditText)findViewById(R.id.EditText03));
            arrayOfEditText[4] = ((EditText)findViewById(R.id.EditText04));
            arrayOfEditText[5] = ((EditText)findViewById(R.id.EditText05));
            arrayOfEditText[6] = ((EditText)findViewById(R.id.EditText06));
            arrayOfEditText[7] = ((EditText)findViewById(R.id.EditText07));
            arrayOfEditText[8] = ((EditText)findViewById(R.id.EditText08));
            arrayOfEditText[9] = ((EditText)findViewById(R.id.EditText09));
            arrayOfEditText[10] = ((EditText)findViewById(R.id.EditText10));

            EditText[] arrayOfEditText1 = new EditText[11];
            arrayOfEditText1[1] = ((EditText)findViewById(R.id.EditText11));
            arrayOfEditText1[2] = ((EditText)findViewById(R.id.EditText12));
            arrayOfEditText1[3] = ((EditText)findViewById(R.id.EditText13));
            arrayOfEditText1[4] = ((EditText)findViewById(R.id.EditText14));
            arrayOfEditText1[5] = ((EditText)findViewById(R.id.EditText15));
            arrayOfEditText1[6] = ((EditText)findViewById(R.id.EditText16));
            arrayOfEditText1[7] = ((EditText)findViewById(R.id.EditText17));
            arrayOfEditText1[8] = ((EditText)findViewById(R.id.EditText18));
            arrayOfEditText1[9] = ((EditText)findViewById(R.id.EditText19));
            arrayOfEditText1[10] = ((EditText)findViewById(R.id.EditText20));

            for(int i=1;i<=nos;i++)
            {
                if(arrayOfEditText[i].getText().toString().equals("")||arrayOfEditText1[i].getText().toString().equals(""))
                {
                    Toast.makeText(getApplicationContext(), "Dont leave points empty", 0).show();
                }
                else
                {
                    calcul();
                }
            }   }   public void calcul()    {       EditText[] arrayOfEditText = new EditText[11];
            arrayOfEditText[1] = ((EditText)findViewById(R.id.EditText01));
            arrayOfEditText[2] = ((EditText)findViewById(R.id.EditText02));
            arrayOfEditText[3] = ((EditText)findViewById(R.id.EditText03));
            arrayOfEditText[4] = ((EditText)findViewById(R.id.EditText04));
            arrayOfEditText[5] = ((EditText)findViewById(R.id.EditText05));
            arrayOfEditText[6] = ((EditText)findViewById(R.id.EditText06));
            arrayOfEditText[7] = ((EditText)findViewById(R.id.EditText07));
            arrayOfEditText[8] = ((EditText)findViewById(R.id.EditText08));
            arrayOfEditText[9] = ((EditText)findViewById(R.id.EditText09));
            arrayOfEditText[10] = ((EditText)findViewById(R.id.EditText10));

            EditText[] arrayOfEditText1 = new EditText[11];
            arrayOfEditText1[1] = ((EditText)findViewById(R.id.EditText11));
            arrayOfEditText1[2] = ((EditText)findViewById(R.id.EditText12));
            arrayOfEditText1[3] = ((EditText)findViewById(R.id.EditText13));
            arrayOfEditText1[4] = ((EditText)findViewById(R.id.EditText14));
            arrayOfEditText1[5] = ((EditText)findViewById(R.id.EditText15));
            arrayOfEditText1[6] = ((EditText)findViewById(R.id.EditText16));
            arrayOfEditText1[7] = ((EditText)findViewById(R.id.EditText17));
            arrayOfEditText1[8] = ((EditText)findViewById(R.id.EditText18));
            arrayOfEditText1[9] = ((EditText)findViewById(R.id.EditText19));
            arrayOfEditText1[10] = ((EditText)findViewById(R.id.EditText20));
                for(i=1;i<=nos;i++)
                {
                  //perform calculation
                }   }

now the logic to be performed in the //perform calculation area is..

arrayofedittext[1]*arrayofedittext1[1] + arrayofedittext[2]*arrayofedittext1[2] + arrayofedittext[3]*arrayofedittext1[3] + etc based on nos / arrayofedittext[1] + arrayofedittext[2] + arrayofedittext[3] + etc based on nos

so can someone help me complete this coding?? 🙂

Answer 1

The less times you perform the same action the faster your app will run. So make EditText[] arrayOfEditText and EditText[] arrayOfEditText1 class-scoped variables, define them once in onCreate() and you won’t have to use findViewById() on R.id.EditText** after that point.

Here’s a function that checks if any of the rows in the calculation are empty, if not you then total will have what you want.

public void calculateTotal() {
    String first;
    String second;

    double firstNum;
    double numerator = 0;
    double denominator = 0;

    // This loops counts from nos down to 1. It checks for empty strings and 
    //   sums up the numerator and denominator along the way.
    for(int index = nos; index > 0; index--) {
        first = arrayOfEditText[index].getText().toString();
        second = arrayOfEditText1[index].getText().toString();

        if(first.isEmpty() || second.isEmpty()) {
            Toast.makeText(getApplicationContext(), "Dont leave any points empty (" + (index + 1) + ")", Toast.LENGTH_LONG).show();
            return; // Invalid input, warn user and bail out of function!
        }

        firstNum = Double.parseDouble(first);
        numerator += firstNum * Double.parseDouble(second);
        denominator += firstNum;
    }

    // Do something with total
    double total = numerator / denominator;
}

Finer Points

Define arrayOfEditText and arrayOfEditText1 to be visible for the entire class like this:

public class Example extends Activity {
    EditText[] arrayOfEditText = new EditText[11];
    EditText[] arrayOfEditText1 = new EditText[11];
    ...

        @Override
        public void onCreate(Bundle savedInstanceState) 
        {
            ...  
            arrayOfEditText[1] = (EditText) findViewById(R.id.EditText01);
            etc, etc...

You should know that an array is a zero-index list. So the first entries in your arrays (arrayOfEditText and arrayOfEditText1) are null, if you ever try and reference arrayOfEditText[0] expecting an EditText your app will crash.

Lastly this code assumes that every EditText is a valid Double, if you don’t restrict non-numeric entries already adding a check is quite simple.