how to toast a message if editText is empty by clicking button?

Question

i have 2 edit Text in my application, 1 button to add the input numbers in the edit Text and 1 text view to display the result. I would like to put a toast message if my edit te

Answer 1

You can try this two function for string empty, not empty or null. It is simple return true or false. It is very use for all projects.

if(isEmpty(edittext.getText().toString())){
       // your Toast message if string is empty
}


if(isNotEmpty(edittext.getText().toString())){
      // your Toast message if string is not empty
}


 public static boolean isEmpty(String str) {

        if (str == null)
            return true;
        else if (str.toString().trim().length() == 0)
            return true;

        return false;
    }

    public static boolean isNotEmpty(String str) {

        if (str == null)
            return false;
        else if (str.toString().trim().length() == 0)
            return false;

        return true;
    } 

Answer 2

when user clicks button check:

if (editText1.getText().toString().trim().length() <= 0) {
    Toast.makeText(MainActivity.this, "It's empty", Toast.LENGTH_SHORT).show();
}

trim it to avoid blank spaces.

Answer 3

Add to your click listener check

Toast toast = Toast.makeText(MainActivity.this, "Your Message", Toast.LENGTH_SHORT);
toast.show();

Answer 4

Your code will be:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    final EditText editText1 = (EditText)findViewById(R.id.editText1);
    final EditText editText2 = (EditText)findViewById(R.id.editText2);
    Button button1 = (Button)findViewById(R.id.button1);
    final TextView textView1 = (TextView)findViewById(R.id.textView1);
    textView1.setText(" ");

    button1.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {        
            if(editText1.getText().toString().trim().length() == 0 || editText2.getText().toString().trim().length() == 0) {
                Toast.makeText(this,"Edittext is null",Toast.LENGTH_SHORT).show();
            }
            else {
                  double edit1 = Double.valueOf(editText1.getText().toString());  
                  double edit2 = Double.valueOf(editText2.getText().toString());
                  double text = edit1 + edit2;
                  textView1.setText(String.valueOf(text));
            }
        });
    }
}

Answer 5

To create and show a Toast use this code:

Toast.makeText(this, "Please input number", Toast.LENGTH_LONG).show();

In order to work properly, you should replace this code:

if (editText1.equals("")) {
    editText1.setError("please input number");
}
if (editText2.equals("")) {
    editText2.setError("please input number");
}

with this:

if (editText1.getText().toString().length() == 0 || editText1.getText().toString().length() == 1) {
    Toast.makeText(this, "Please input number", Toast.LENGTH_LONG).show();
}