EditText Capitalization: How to Capitalize First Letter on Android?

Introduction

When creating an Android app with EditText fields, it's common to want to capitalize the first letter of each word entered by the user. This can improve the appearance and readability of the text. In this article, we'll explore how to achieve this using Java code.

Using InputFilter

One way to capitalize the first letter of each word is to use an InputFilter. An InputFilter is a class that can be used to modify input as it is entered into an EditText widget. We can use an InputFilter to intercept each character as it is typed and change it to its capitalized equivalent.

Here's an example of using an InputFilter to capitalize each word:

InputFilter capitalizeFilter = new InputFilter() {
    public CharSequence filter(CharSequence source, int start, int end,
            Spanned dest, int dstart, int dend) {
        StringBuilder builder = new StringBuilder();
        boolean capitalize = true;

        for (int i = start; i < end; i++) {
            char c = source.charAt(i);

            if (capitalize && Character.isLetter(c)) {
                builder.append(Character.toUpperCase(c));
                capitalize = false;
            } else {
                builder.append(c);
            }

            if (Character.isWhitespace(c)) {
                capitalize = true;
            }
        }

        return builder.toString();
    }
};

editText.setFilters(new InputFilter[] { capitalizeFilter });

This code creates an InputFilter object that capitalizes each word as it is entered into an EditText field. It then sets this filter on the EditText field using the setFilters() method.

Using android:inputType

Another way to capitalize the first letter of each word is to use the android:inputType attribute in the XML layout file. This attribute can be set to "textCapWords" to automatically capitalize the first letter of each word entered into the EditText field.

Here's an example of using the android:inputType attribute to capitalize each word:

This code sets the android:inputType attribute to "textCapWords" on the EditText field. This will automatically capitalize the first letter of each word entered into the field.

Conclusion

In this article, we explored two ways to capitalize the first letter of each word entered into an EditText field in an Android app. We used an InputFilter to intercept each character as it is typed and capitalize it if it is the first letter of a word. We also used the android:inputType attribute to automatically capitalize the first letter of each word entered into the field. These techniques can help improve the appearance and readability of text in an Android app.