addTextChangedListener

addTextChangedListener is a method in Android that allows you to add a listener to an EditText view, which will be notified whenever the text in the EditText changes. This method takes an instance of TextWatcher as a parameter, which is an interface that defines three methods:

- beforeTextChanged: Called before the text is changed.
- onTextChanged: Called when the text is changed.
- afterTextChanged: Called after the text is changed.

You can use these methods to perform actions such as validating the text, updating a counter, or filtering a list based on the text entered.

Here's an example of how to use addTextChangedListener to set up a listener for an EditText view:

EditText editText = findViewById(R.id.edit_text);

editText.addTextChangedListener(new TextWatcher() {
    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {
        // Do something before the text is changed
    }

    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) {
        // Do something when the text is changed
    }

    @Override
    public void afterTextChanged(Editable s) {
        // Do something after the text is changed
    }
});