Base64 Encode and Decode

Base64 is used for converting arbitrary binary data to ASCII text so, that it's become easier to transmitted the data over the network like e-mail and HTML form data.

It is a group of similar binary-to-text encoding schemes that represent binary data in an ASCII string format by translating it into a radix-64 representation (Source Wikipedia).

I will share, how you can achieve base64 encoding  and decoding in C#, Java and Objective-C programming Languages.

So follow below code snippet for C#.

Encode
public static string Base64Encode(string plainText) {
  var plainTextBytes = System.Text.Encoding.UTF8.GetBytes(plainText);
  return System.Convert.ToBase64String(plainTextBytes);
}


Decode
public static string Base64Decode(string base64EncodedData) {
  var base64EncodedBytes = System.Convert.FromBase64String(base64EncodedData);
  return System.Text.Encoding.UTF8.GetString(base64EncodedBytes);
}

For Java See below code:
Note:  Java 8 now supports BASE64 Encoding and Decoding. You can use the following classes:

1.  java.util.Base64,
2.  java.util.Base64.Encoder and 
3. java.util.Base64.Decoder

Method 1
// encode with padding
String encoded = Base64.getEncoder().encodeToString(someByteArray);

// encode without padding
String encoded = Base64.getEncoder().withoutPadding().encodeToString(someByteArray);

// decode a String
byte [] barr = Base64.getDecoder().decode(encoded); 

Method 2
import java.io.UnsupportedEncodingException;    
import javax.xml.bind.DatatypeConverter;

public class EncodeString64 {

    public static void main(String[] args) throws UnsupportedEncodingException {

        String str = "77+9x6s=";
        // encode data using BASE64
        String encoded = DatatypeConverter.printBase64Binary(str.getBytes());
        System.out.println("encoded value is \t" + encoded);

        // Decode data 
        String decoded = new String(DatatypeConverter.parseBase64Binary(encoded));
        System.out.println("decoded value is \t" + decoded);

        System.out.println("original value is \t" + str);

    }

}

For Objective C:

NSString *plainString = @"foo";

Encoding

NSData *plainData = [plainString dataUsingEncoding:NSUTF8StringEncoding];
NSString *base64String = [plainData base64EncodedStringWithOptions:0];
NSLog(@"%@", base64String); // Zm9v

Decoding

NSData *decodedData = [[NSData alloc] initWithBase64EncodedString:base64String options:0];
NSString *decodedString = [[NSString alloc] initWithData:decodedData encoding:NSUTF8StringEncoding];
NSLog(@"%@", decodedString); // foo