Converting String to Double in Android

Question

Trying to get double values from an EditText and manipulate them before passing them to another Intent. Not using primitive data type so I can use toString methods.

Problem is when I include the protein=Double.valueOf(p).doubleValue(); style commands, the program force closes immediately without leaving any info in the logcat.If I comment them out and set some dummy data like protein = 1.0; it works with no problems. Same happens with primitive data types and parse double. This code works perfectly with dummy data in normal java. What am I doing wrong?

EditText txtProt, txtCarb, txtFat, txtFiber, txtPoints;
String p, c, f, fi;
Double protein, carbs, fat, fiber;
double temp;
Integer points;

@Override
public void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     Log.v("Create Prompt", "ready for layout");
     setContentView(R.layout.main);
     Log.v("Layout Created", "ready for variable assignment");
     txtProt = (EditText) findViewById(R.id.Protein);
     txtCarb = (EditText) findViewById(R.id.Carbs);
     txtFat = (EditText) findViewById(R.id.Fat);
     txtFiber = (EditText) findViewById(R.id.Fiber);
     txtPoints = (EditText) findViewById(R.id.Points);
     btnCalc = (Button) findViewById(R.id.Calc);
     Log.v("Variables Assigned", "ready for double assignment");

     p = txtProt.getText().toString();
     c = txtCarb.getText().toString();
     f = txtFat.getText().toString();
     fi = txtFiber.getText().toString();


     protein=Double.valueOf(p).doubleValue();
     carbs=Double.valueOf(c).doubleValue();
     fat=Double.valueOf(f).doubleValue();
     fiber=Double.valueOf(fi).doubleValue();
     Log.v("Doubles parsed", "ready for calculations");
     //these are the problem statements

     protein = 1.0;
     carbs = 1.0;
     fat = 1.0;
     fiber = 1.0;

     protein *= 16;
     carbs *= 19;
     fat *= 45;
     fiber *= 14;

     temp = protein + carbs + fat - fiber;
     temp = temp/175;

     points = new Integer((int) temp);

Answer 1

try this:

double d= Double.parseDouble(yourString);

Answer 2

You seem to assign Double object into native double value field. Does that really compile?

Double.valueOf() creates a Double object so .doubleValue() should not be necessary.

If you want native double field, you need to define the field as double and then use .doubleValue()

Answer 3

  kw=(EditText)findViewById(R.id.kw);
    btn=(Button)findViewById(R.id.btn);
    cost=(TextView )findViewById(R.id.cost);


            btn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) { cst =  Double.valueOf(kw.getText().toString());
            cst = cst*0.551;
            cost.setText(cst.toString());
        }
    });

Answer 4

i have a similar problem. for correct formatting EditText text content to double value i use this code:

try {
        String eAm = etAmount.getText().toString();
        DecimalFormat dF = new DecimalFormat("0.00");
        Number num = dF.parse(eAm);
        mPayContext.amount = num.doubleValue();
    } catch (Exception e) {
        mPayContext.amount = 0.0d;
    }

this is independet from current phone locale and return correct double value.

hope it's help;

Answer 5

I would do it this way:

try {
  txtProt = (EditText) findViewById(R.id.Protein); // Same
  p = txtProt.getText().toString(); // Same
  protein = Double.parseDouble(p); // Make use of autoboxing.  It's also easier to read.
} catch (NumberFormatException e) {
  // p did not contain a valid double
}

EDIT: "the program force closes immediately without leaving any info in the logcat"

I don't know bout not leaving information in the logcat output, but a force-close generally means there's an uncaught exception - like a NumberFormatException.

Answer 6

What about using the Double(String) constructor? So,

protein = new Double(p);

Don't know why it would be different, but might be worth a shot.