CheckBox

• A CheckBox is a special kind of button in Android which has two states either checked or unchecked.

• The Checkbox is a very common widget to be used in Android and a very good example is the “Remember me” option in any kind of Login activity of an app which asks the user to activate or deactivate that service.

• There are many other uses of the CheckBox widget like offering a list of options to the user to choose from and the options are mutually exclusive i.e., the user can select more than one option.

• This feature of the CheckBox makes it a better option to be used in designing multiple-choice questions application or survey application in android.

• CheckBox belongs to android.widget.CheckBox class. Android CheckBox class is the subclass of CompoundButton class.

• It is generally used in a place where user can select one or more than choices from a given list of choices. For example, selecting hobbies.

• Kotlin

package com.geeksforgeeks.checkbox; 
import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle; 
import android.view.View; 
import android.widget.CheckBox; 
import android.widget.Toast; 

public class MainActivity extends AppCompatActivity { 
	lateinit var ch : CheckBox
	lateinit var ch1 : CheckBox
  lateinit var ch2 : CheckBox
  lateinit var ch3 : CheckBox 
  lateinit var btn : Button

	lateinit var msg = ""
	@Override
	protected void onCreate(Bundle savedInstanceState) { 
		super.onCreate(savedInstanceState); 
		setContentView(R.layout.activity_main); 

		ch=findViewById(R.id.checkBox)
		ch1=findViewById(R.id.checkBox2) 
		ch2=findViewById(R.id.checkBox3) 
		ch3=findViewById(R.id.checkBox4)
		btn =findViewById(R.id.submit)

		btn.setOnClickListener{
		// Concatenation of the checked options in if 		
		// isChecked() is used to check whether 
		// the CheckBox is in true state or not. 

		if(ch.isChecked())		 
			msg = msg + " Painting "; 
		if(ch1.isChecked()) 
			msg = msg + " Reading "; 
		if(ch2.isChecked()) 
			msg = msg + " Singing "; 
		if(ch3.isChecked()) 
			msg = msg + " Cooking "; 

		// Toast is created to display the 
		// message using show() method. 
		Toast.makeText(this, msg + "are selected",Toast.LENGTH_LONG).show(); 
	} 

}