Code for Identifying a Single letter?

Question

Hi there I am a bit of a noob at programming but I want to create an IF statement , whether or not a textview , (which i have already referenced) contains a letter in side of it and only that letter for example I want to change any textview which has a "1" in it whats the code? this is what I have got can some one please help me complete it?

if ("!".contains(stuff.getText()) {
    stuff.setText("Incorrect Symbol");
}else {

}

I know that I can use the keyboard to control what can be entered but I would prefer that someone would tell me how to do it this way. By the way I keep on get a little red line over stuff.gettext so can some one please tell me the problem?

Answer 1

I think there are two main issues here:

• You are a little confused with the syntax
• Android often uses CharSequence for its text values, rather than String, so it makes it a bit more complicated.

Assuming "stuff" is your TextView, you can do the following:

String stuffText = stuff.getText().toString();
if(stuffText.contains("1")) {
    stuff.setText("Incorrect Symbol");
} else {

}

I'm not sure why you are getting the red line on stuff.getText(), but that line should have a corresponding compiler error that you can check in the appropriate view (assuming you're in an IDE like Eclipse).

And as for overall design, this is a bad way to go. You can specify what characters the field accepts by setting up the XML:

<EditText xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:inputType="phone|numberSigned"
    android:digits="0123456789" />

If you really want to have the feedback, you may want to use TextWatcher, so you can respond as the user types.

Answer 2

Use String.contains("yourCharacter") to check if yourCharacter is present in the String or not.

So, your code will look like

if (stuff.getText().contains("!")) {
    stuff.setText("Incorrect Symbol"); // your text contains the symbol
}else {
    ..... // your text does not contain the symbol
}