Demonstration How you can implement Body Mass Index programically on android

MainActivity.java

package com.mostafaAnter.bmi;

import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        final  EditText x1=(EditText)findViewById(R.id.editText1);
        final  EditText x2=(EditText)findViewById(R.id.editText2);
        Button b=(Button)findViewById(R.id.button1);
        Button b1=(Button)findViewById(R.id.button2);
        b.setOnClickListener(new OnClickListener() {
			
			@Override
			public void onClick(View v) {
			double d1=Double.parseDouble(x1.getText().toString());
			double d2=Double.parseDouble(x2.getText().toString());
			double d3=d2/100;
			double d4=d1/(d3*d3);
			String s ="";
			if (d4<20)
				s="You are Thin";
			if (d4==20)
				s="You are fitness";
			if (d4>20&&d4<25)
				s="You are fitness";
			if (d4>25&&d4<30)
				s="You are overweight";
			if (d4>30&&d4<40)
				s="You are obesity";
			if (d4>40)
				s=" obese";
			
			
			Toast.makeText(MainActivity.this, "BMI is : " + d4 + "\n" + s, Toast.LENGTH_LONG).show();
			
			
				
			}
		});
        b1.setOnClickListener(new OnClickListener() {
			
			@Override
			public void onClick(View v) {
			startActivity(new Intent(MainActivity.this, Second.class));
				
			}
		});
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
    
}