In traditional OOP, if we wanted to get or set an object's private member, we would need to write a public method to do the job.
The reason behind making a member data private and then accessing it through a public method is to avoid the implementing-user to access it directly.
There can be many reasons for prohibiting direct access to member data to the implementing-code.
For example, you may want a radius of a Circle to be within the range of 10 - 500.

C++: Traditional OOP

class Circle
 {
        private:
          int radius;

        public:
          Circle(int radius = 15)
           {
                  setRadius(radius);
           }

          void setRadius(int radius)
           {
                  if (radius < 10 || radius > 500)
                   {
                          this->radius = -1;
                          cout << "Radius must be within the range of 10 - 500" << endl;
                   }
                  else
                   this->radius = radius;
           }

          int getRadius()
           {
                  return this->radius;
           }
 }

void main()
 {
        Circle c = Circle();
        c.setRadius(25);
        cout << c.getRadius();
 }

C++

In languages like PHP & Python & PERL which have a weak type system, a further check of the data type may be necessary.
But for Python unfortunately even traditional getter & setter methods cannot be implemted because Python doesn't have a public or private. Everything is public by default - though a member can be made private by prefixing two underscores to it. But this is only for convention, it doesn't really serve its true purpose.

PHP 5 and C# .NET have a getter and setter method feature, making it look like we're accessing the data member directly.

PHP

<?php
class Circle
 {
        private $radius; # integer

        # Constructor
        public function __construct($radius = 15)
         {
                self::__set('radius', $radius);
         }

        # Setter
        public function __set($name, $value)
         {
                switch ($name)
                 {
                        case 'radius':

                          if (!is_numeric($value)) # is_int() for strong type checking
                           throw new Exception('Radius must be of a numeric type');

                          if ($value < 10 || $value > 500)
                           throw new Exception('Radius must be within the range of 10 - 500');

                          $this->radius = $value;

                        break;

                        default:
                          throw new Exception("Attempt to set a non-existing property: $name");
                        break;
                 }
         }

        # Getter
        public function __get($name)
         {
                if (in_array($name, array('radius')))
                 return $this->$name;

                switch ($name)
                 {
                        default:
                          throw new Exception("Attempt to get a non-existing property: $name");
                        break;
                 }
         }

 }

$c = new Circle();
$c->radius = 25;
echo $c->radius;
>

PHP 5.x

C#

using System;

public class Circle
 {
        private int __radius = 5;

        public Circle()
         {
         }

        public Circle(int radius)
         {
                this.radius = radius; // This will call the property defined below
         }

        public int radius // Property getter/setter name cannot be the same as the member variable name
         {
                get
                 {
                        return __radius;
                 }

                set
                 {
                        if (value < 10 || value > 500)
                         throw new Exception("Radius must be within the range of 10 - 500");

                        __radius = value;
                 }
         }
 }

public class main
 {
        public static void Main(string[] args)
         {
                Circle c = new Circle(); // Circle c = new Circle(5); will throw an Exception
                c.radius = 25;
                Console.WriteLine(c.radius);
         }
 }

.NET 2.0

C# .NET 3.0 has introduced Automatic Properties where you don't need to specify code for the getter & setter - the compiler takes generates the method body.

JavaScript does seem to have a getter and setter method which I came across just now when searching for the official source to Java 7's new features' documentation, but :

• only within an object initializer - not inside a function so it doesn't seem to be of much use as we can't create instances
• doesn't hide the member from being accessed directly
• doesn't work in IE.

JavaScript

var someObj =
 {
        a : 7,
        get b()
         {
                return this.a * 3;
         },
        set c(x)
         {
                this.a = x / 2;
         }
 }

someObj.foo1 = function()
 {
        //
 }

alert(someObj.a); // 7
alert(someObj.b); // 21
someObj.c = 5; alert(someObj.a); // 2.5
someObj.foo1();

JavaScript 1.5

The Getter & Setter feature does not seem to be a much "wanted" feature in the Java community.
Still, this has been proposed by Rémi Forax for JDK 7.

Java: Proposal

public class Circle
 {
        private int __radius = 5;

        public Circle()
         {
         }

        public Circle(int radius)
         {
                this.radius = radius; // This will call the property defined below
         }

        public property int radius // Property getter/setter name cannot be the same as the member variable name
         {
                get
                 {
                        return __radius;
                 }

                set (int radius)
                 {
                        if (radius < 10 || radius > 500)
                         throw new Exception("Radius must be within the range of 10 - 500");

                        __radius = radius;
                        // firePropertyChange(radius);
                 }
         }

        public static void main(String[] args)
         {
                Circle c = new Circle(2); // Circle c = new Circle(5); will throw an Exception
                c.radius = 25;
                System.out.println(c.radius);
         }
 }

JDK 7

PHP

<?php
class RandomText
 {
        const RAND_NUMBERS       = 1;
        const RAND_SMALL_LETTERS = 2;
        const RAND_CAP_LETTERS   = 4;
        const RAND_ALL           = 7;

        /**
         * @access public
         * @param Type (INT) One of the random constants RAND_*
         * @NoOfChars [INT] Optional - No of characters to generate
         * @return (string) random string
         * @example echo RandomText::Random_String(RandomText::RAND_NUMBERS + RandomText::RAND_CAP_LETTERS, 25);
         */
 	public static function Random_String($Type = self::RAND_NUMBERS, $NoOfChars = 6)
 	 {
 	 	$strList = array();

 	 	// Convert to binary format and find out what combination of random characters are required
 	 	$binType = base_convert($Type, 10, 2);

 	 	// Loop through the bits from Right To Left
 	 	for ($i = strlen($binType) - 1; $i >= 0; $i--)
 	 	 {
 	 	 	if ($binType[$i])
 	 	 	 {
 	 	 	 	switch (pow(2, strlen($binType) - $i - 1))
 	 	 	 	 {
 	 	 	 	 	default:

 	 	 	 	 	case self::RAND_NUMBERS:
 	 	 	 	 	 $Ascii_Range = array(48, 57);  // Numbers - Characters 0 to 9
 	 	 	 	 	break;

 	 	 	 	 	case self::RAND_SMALL_LETTERS:
   	 	 	 	 	 $Ascii_Range = array(97, 122); // Small Letters - Characters a to z
 	 	 	 	 	break;

 	 	 	 	 	case self::RAND_CAP_LETTERS:
 	 	 	 	 	 $Ascii_Range = array(65, 90);  // Capital Letters - Characters A to Z
 	 	 	 	 	break;
 	 	 	 	 }

 	 	 	 	for ($j = $Ascii_Range[0]; $j <= $Ascii_Range[1]; $j++)
 	 	 	 	 $strList[] = chr($j);
 	 	 	 }
 	 	 }

 	 	$RndString = "";
 	 	for ($i = 0; $i < $NoOfChars; $i++)
 	 	 $RndString .= $strList[rand(0, count($strList) - 1)];

 	 	return $RndString;
 	 }
 }

echo RandomText::Random_String(RandomText::RAND_NUMBERS + RandomText::RAND_CAP_LETTERS, 25);
?>

PHP 5.2.3

C#

using System;
using System.Text;

public class RandomText
 {
        public const int RAND_NUMBERS       = 1;
        public const int RAND_SMALL_LETTERS = 2;
        public const int RAND_CAP_LETTERS   = 4;
        public const int RAND_ALL           = 7;

        public static string Random_String()
         {
                return Random_String(RAND_NUMBERS, 6);
         }

        public static string Random_String(int Type)
         {
                return Random_String(Type, 6);
         }

        public static string Random_String(int Type, int NoOfChars)
         {
                StringBuilder strList = new StringBuilder();
                int[] Ascii_Range;
                int i;

                // Convert to binary format and find out what combination of random characters are required
                string binType = Convert.ToString(Type, 2);

                // Loop through the bits from Right To Left
                for (i = binType.Length - 1; i >= 0; i--)
                 {
                        if (binType[i] == '1')
                         {
                                switch ((int)Math.Pow(2, binType.Length - i - 1))
                                 {
                                        default:

                                        case RAND_NUMBERS:
                                         Ascii_Range = new int[] {48, 57};  // Numbers - Characters 0 to 9
                                        break;

                                        case RAND_SMALL_LETTERS:
                                         Ascii_Range = new int[] {97, 122};  // Small Letters - Characters a to z
                                        break;

                                        case RAND_CAP_LETTERS:
                                         Ascii_Range = new int[] {65, 90};  // Capital Letters - Characters A to Z
                                        break;
                                 }

                                for (int j = Ascii_Range[0]; j <= Ascii_Range[1]; j++)
                                 strList.Append((char)j);
                         }
                 }

 	 	StringBuilder RndString = new StringBuilder();
 	 	Random rnd = new Random();
 	 	
 	 	for (i = 0; i < NoOfChars; i++)
 	 	 RndString.Append(strList[rnd.Next(strList.Length - 1)]);

 	 	return RndString;
         }

        public static void Main(string[] args)
         {
                Console.WriteLine(RandomText.Random_String(RandomText.RAND_NUMBERS + RandomText.RAND_CAP_LETTERS, 25));
         }
 }

.NET 2.0

Java

import java.io.*;
import java.util.Random;

public class RandomText
 {
        public static final int RAND_NUMBERS       = 1;
        public static final int RAND_SMALL_LETTERS = 2;
        public static final int RAND_CAP_LETTERS   = 4;
        public static final int RAND_ALL           = 7;

        public static String Random_String()
         {
                return Random_String(RAND_NUMBERS, 6);
         }

        public static String Random_String(int Type)
         {
                return Random_String(Type, 6);
         }

        public static String Random_String(int Type, int NoOfChars)
         {
                StringBuilder strList = new StringBuilder();
                int[] Ascii_Range;
                int i;

                // Convert to binary format and find out what combination of random characters are required
                String binType = Integer.toString(Type, 2); // Type.toString(2);

                // Loop through the bits from Right To Left
                for (i = binType.length() - 1; i >= 0; i--)
                 {
                        if (binType.charAt(i) == '1')
                         {
                                switch ((int)Math.pow(2, binType.length() - i - 1))
                                 {
                                        default:

                                        case RAND_NUMBERS:
                                         Ascii_Range = new int[] {48, 57};  // Numbers - Characters 0 to 9
                                        break;

                                        case RAND_SMALL_LETTERS:
                                         Ascii_Range = new int[] {97, 122};  // Small Letters - Characters a to z
                                        break;

                                        case RAND_CAP_LETTERS:
                                         Ascii_Range = new int[] {65, 90};  // Capital Letters - Characters A to Z
                                        break;
                                 }

                                for (int j = Ascii_Range[0]; j <= Ascii_Range[1]; j++)
                                 strList.append((char)j);
                         }
                 }

                StringBuilder RndString = new StringBuilder();
                Random rnd = new Random();

                for (i = 0; i < NoOfChars; i++)
                 RndString.append(strList.charAt(rnd.nextInt(strList.length() - 1)));

                return RndString.toString();
         }

        public static void main(String[] args) throws Exception
         {
                System.out.println(RandomText.Random_String(RandomText.RAND_NUMBERS + RandomText.RAND_CAP_LETTERS, 25));
         }
 }

JDK 6.0

JavaScript

function RandomText()
 {
        this.RAND_NUMBERS       = 1;
        this.RAND_SMALL_LETTERS = 2;
        this.RAND_CAP_LETTERS   = 4;
        this.RAND_ALL           = 7;

        this.Random_String = function(Type, NoOfChars)
         {
                var strList = "";
                var Ascii_Range;
                var i;

                // Convert to binary format and find out what combination of random characters are required
                binType = Type.toString(2);

                // Loop through the bits from Right To Left
                for (i = binType.length - 1; i >= 0; i--)
                 {
                        if (binType[i] == '1')
                         {
                                switch (Math.pow(2, binType.length - i - 1))
                                 {
                                        default:

                                        case this.RAND_NUMBERS:
                                         Ascii_Range = new Array(48, 57);  // Numbers - Characters 0 to 9
                                        break;

                                        case this.RAND_SMALL_LETTERS:
                                         Ascii_Range = new Array(97, 122); // Small Letters - Characters a to z
                                        break;

                                        case this.RAND_CAP_LETTERS:
                                         Ascii_Range = new Array(65, 90);  // Capital Letters - Characters A to Z
                                        break;
                                 }

                                for (var j = Ascii_Range[0]; j <= Ascii_Range[1]; j++)
                                 strList += String.fromCharCode(j);
                         }
                 }

                var RndString = "";
                for (i = 0; i < NoOfChars; i++)
                 RndString += strList[Math.floor(Math.random() * strList.length)];

                return RndString;
         }
 }

var oRandomText = new RandomText();
alert(oRandomText.Random_String(oRandomText.RAND_NUMBERS + oRandomText.RAND_CAP_LETTERS, 25));

JavaScript 1.5

Python

import array
import random

def int2bin(n):
    "Convert an integer to binary - no built-in function"
    bStr = ''
    while n > 0:
          bStr = str(n % 2) + bStr
          n = n >> 1
    return bStr

class RandomText:

      RAND_NUMBERS       = 1;
      RAND_SMALL_LETTERS = 2;
      RAND_CAP_LETTERS   = 4;
      RAND_ALL           = 7;

      def Random_String(Type = RAND_NUMBERS, NoOfChars = 6):
          strList = array.array('c', '')

          # Convert to binary format and find out what combination of random characters are required
          binType = int2bin(Type)

          # Loop through the bits from Right To Left
          for i in range(len(binType) - 1, -1, -1):

              if binType[i] == '1':

                 x = 2 ** (len(binType) - i - 1)

                 if x == RandomText.RAND_NUMBERS:
                    Ascii_Range = [48, 57]   # Numbers - Characters 0 to 9
                 elif x == RandomText.RAND_SMALL_LETTERS:
                    Ascii_Range = [97, 122]  # Small Letters - Characters a to z
                 elif x == RandomText.RAND_CAP_LETTERS:
                    Ascii_Range = [65, 90]   # Capital Letters - Characters A to Z
                 else:
                    Ascii_Range = [48, 57]   # Numbers - Characters 0 to 9

                 for j in range(Ascii_Range[0], Ascii_Range[1] + 1):
                    strList.append(chr(j))

              RndString = array.array('c', '')

              for i in range(0, NoOfChars):
                  RndString.append(strList[random.randint(0, len(strList) - 1)])

          return RndString.tostring()

      Random_String = staticmethod(Random_String)


print RandomText.Random_String(RandomText.RAND_NUMBERS + RandomText.RAND_CAP_LETTERS, 25)

Python 2.5