Issue With Empty Edittext

I have an Activity with an EditText, Button and TextView. If I write some numbers and click the button, the TextView shows the result of the calculation. If the EditText is empty

Solution 1:

You just need to do a check on what the user has typed:

String input = editText.getText().toString();

if(input == null || input.trim().equals("")){
      Toast.makeText(context, "Sorry you did't type anything"), Toast.LENGTH_SHORT).show();
}

EDIT

If you have a float, you have to do the check before you parse the float:

String input = editText.getText().toString();

if(input == null || input.trim().equals("")){
      // Toast messagereturn;
}
float num1 = Float.parseFloat(input);

or

try{

   float num1 = Float.parseFloat(numA.getText().toString());

} catch (NumberFormatException e) {
   // Toast message - you cannot get a float from that inputreturn;
}

Solution 2:

You need to make sure that the EditText isn't empty. Try using something like:

EditTexteditText= (EditText) findViewById(R.id.edittext);
Stringtext= editText.getText().toString();
if (text == null || text.equals("")) {
    Toast.makeText(this, "You did not enter a number", Toast.LENGTH_SHORT).show();
    return;
}

Solution 3:

Pretty simple. Before you start calculations you should call the following code:

if (editText.getText().length() > 0) {
    // do the calculations
}

This way you'll know whether there is something in your EditText or not. If it's empty you can show an AlertDialog or a Toast to help your users. Hope this helps.