<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="//schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">
    <TextView
        android:id="@+id/idLabel"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Enter word"/>
    <EditText
        android:id="@+id/idEntry"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:background="@android:drawable/editbox_background"
        android:layout_below="@id/idLabel"/>
    <Button
        android:id="@+id/idOk"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/idEntry"
        android:layout_alignParentRight="true"
        android:layout_marginLeft="10dip"
        android:text="OK" />
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_toLeftOf="@id/idOk"
        android:layout_alignTop="@id/idOk"
        android:text="Cancel" />
</RelativeLayout>

<EditText
        android:id="@+id/myEdit" 
	android:layout_height="wrap_content" android:layout_width="fill_parent"
        android:hint="Some text"
	android:singleLine="true"
</EditText>	

// setHint(CharSequence hint) example
(EditText)findViewById(R.id.myEdit).setHint("My text");
// or int resId as method setHint(int resId) 
EditText myEdit = findViewById(R.id.myEdit);
myEdit.setHint(R.string.app_name);

public class MainClass {
	public static void main(String[] arg) {
		String[] arrayOfString = { "Hello", "people", "hello", "world!" };

		for (int i = 0; // start position , first cycle i == 0
                      i < arrayOfString.length; // if i < 4 (length of array) do loop
                       i++ // incrementation after cycle
                       ){
			System.out.println(arrayOfString[i]); 
                       // i++ incrementation
		}
	}
}

// file name MyFirstClass.java

import java.util.*;
import java.lang.Math;
import java.io.*;
import javax.swing.*;

public class MyFirstClass{ // start of program
  public static void main(String[] args) { // basic  function main

// variables and calculation
int a=2;
int b=3;
int c=Integer.parseInt(JOptionPane.showInputDialog(" Put number: ", "1"));
System.out.println("Number is: "+c);
System.out.println(a+" * "+b+" = "+(a*b));
System.out.println("a^3 "+Math.pow(a,b));

//array
int[] array_my=new int[10];
array_my[0]=3;
array_my[1]=5;
System.out.println("Number of elements "+array_my.length+" 1 + 2 element of array "+(array_my[0]+array_my[1]));

//strings
String txt="Quick red fox";
String txt2=JOptionPane.showInputDialog("Write text: ", "word");
System.out.println("Text is: "+txt2);
String[] count_of_word=txt.split(" ");
System.out.println("Length: "+txt.length()+" Count of words "+count_of_word.length);
System.out.println(txt +" -> "+txt.replace("red","brown"));
System.out.println("First 5 chars of string is: "+ txt.substring(0,5));

//for a if
for(int i=0; i<10;i++){
	if(i==3)System.out.println("i equal "+i);
	}

// file
try {
  File soubor=new File("some_file.txt");
  if(!soubor.exists()){
	System.out.println("File dont exist");
  }
  else { // utf-8 encoding
    BufferedReader in1 = new BufferedReader(new InputStreamReader(new FileInputStream(soubor),"UTF-8"));
    BufferedWriter out1 = new BufferedWriter(new OutputStreamWriter(new FileOutputStream("zapis.txt"),"UTF-8"));
    String str;
      while ((str = in1.readLine())!=null){
        System.out.println(str);
        out1.write(str+"

");
      }
    in1.close();
    out1.close();
   }
 } catch(IOException e){System.out.println("Error " + e);}

// dir
 File pathName = new File("some_dir");
 String[] fileNames = pathName.list();
 if(pathName.exists())
 System.out.println("Name of first file in  \"some_dir\": "+fileNames[0]);
 else System.out.println("dir not exist");

//function
int nResult = calculateMyFc(3,5);
System.out.println("Result of function: "+nResult);

} // end of function main

// new function , you can add to end MyFc = my function
public static int calculateMyFc(int a, int b){
return (a+b);
}

} // end of class of program