Use Length in Android TextView

This example demonstrate about How to use length () in Android textview.

Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.

Step 2 − Add the following code to res/layout/activity_main.xml.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   xmlns:app="http://schemas.android.com/apk/res-auto"
   xmlns:tools="http://schemas.android.com/tools"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:orientation="vertical"
   android:gravity="center"
   tools:context=".MainActivity">
   <EditText
      android:id="@+id/name"
      android:layout_width="match_parent"
      android:hint="Enter name"
      android:layout_height="wrap_content" />
   <Button
      android:id="@+id/click"
      android:text="Click"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content" />
   <TextView
      android:id="@+id/textview"
      android:layout_width="wrap_content"
      android:textSize="25sp"
      android:layout_height="wrap_content" />
</LinearLayout>

In the above code, we have taken the name as Edit text, when user click on button it will take data and check length of entered value is 0 or more than zero than returns last index of “sai”.

Step 3 − Add the following code to src/MainActivity.java

package com.example.myapplication;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
   EditText name;
   Button button;
   TextView text;

   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      name = findViewById(R.id.name);
      button = findViewById(R.id.click);
      text = findViewById(R.id.textview);
      button.setOnClickListener(new View.OnClickListener() {
         @Override
         public void onClick(View v) {
            if (!name.getText().toString().isEmpty()) {
               if (name.getText().toString().length() >= 0) {
                  int index = name.getText().toString().lastIndexOf("sai");
                  text.setText(String.valueOf(index));
               }
            } else {
               name.setError("Plz enter name");
            }
         }
      });
   }
}

Let's try to run your application. I assume you have connected your actual Android Mobile device with your computer. To run the app from android studio, open one of your project's activity files and click Run  icon from the toolbar. Select your mobile device as an option and then check your mobile device which will display your default screen −

In the above result, enter the string as “Krishna sai sai” . It going to checked the leght of string if it is 0 or more than zero condition and it returned the last index of sai as 12.

Click here to download the project code