Android, Validate An Empty Edittext Field

Hi I have a simple temperature converter application where the application crashes whenever the field is empty. I tried some validation I found on S.O but it keeps crashing, so can

Solution 1:

Try this

if (celsiusEdit.getText().toString().matches("")) {
    Toast.makeText(this, "Field cannot be empty", Toast.LENGTH_SHORT).show();
    return;
}else{
  double celsius = Double.valueOf(celsiusEdit.getText().toString());
  double farh = (celsius -32) * 5/9;

  farhEdit.setText(String.valueOf(farh));
}

Solution 2:

Your if statement makes no sense, you should do something like this:

if(celsiusEdit.getText().toString().trim().length() == 0){

However you could run into an issue if a non-number is put into that textbox because

Double celsius =     Double.valueOf(celsiusEdit.getText().toString());

will throw a NumberFormatException, so you should put that in a try.

Solution 3:

You can try and import this class here Android Form Validation Class

This can help you to validate the Form fields, just need to follow the instructions. (: