How to convert a binary to decimal in Swift?

How to convert a binary to decimal in Swift?

I am looking for a simple way to convert a binary number in decimal in Swift. For example, "10" in binary becomes "2" in decimal.

Thanks,

Answer by Todd Agulnick for How to convert a binary to decimal in Swift?

There may be a built-in to do this, but writing the code yourself isn't hard:

func parseBinary(binary: String) -> Int? {      var result: Int = 0        for digit in binary {          switch(digit) {              case "0": result = result * 2              case "1": result = result * 2 + 1              default: return nil          }      }      return result  }  

The function returns an (optional) Int. If you want to get a string instead, you can do the following:

String(parseBinary("10101")!)  -> "21"  

Note the forced unwrapping (!) If the string you provide contains anything other than 0's or 1's, the function returns nil and this expression will blow up.

Or, taking a cue from Leonardo, you can build this as an extension to string:

extension String {      func asBinary() -> Int? {          var result: Int = 0            for digit in self {              switch(digit) {                  case "0": result = result * 2                  case "1": result = result * 2 + 1                  default: return nil              }          }          return result      }  }    "101".asBinary()!  -> 5  

Answer by Martin R for How to convert a binary to decimal in Swift?

You can simply use the BSD library function strtoul(), which converts a string to a number according to a given base:

let binary = "11001"  let number = strtoul(binary, nil, 2)  println(number) // Output: 25  

Answer by Leo Dabus for How to convert a binary to decimal in Swift?

Update: Xcode 7.2 ? Swift 2.1.1

You can implement Martin R's Answer making an extension using C++ function called strtoul as follow:

extension String {      var hexaToInt      : Int    { return Int(strtoul(self, nil, 16))      }      var hexaToDouble   : Double { return Double(strtoul(self, nil, 16))   }      var hexaToBinary   : String { return String(hexaToInt, radix: 2)      }      var decimalToHexa  : String { return String(Int(self) ?? 0, radix: 16)}      var decimalToBinary: String { return String(Int(self) ?? 0, radix: 2) }      var binaryToInt    : Int    { return Int(strtoul(self, nil, 2))       }      var binaryToDouble : Double { return Double(strtoul(self, nil, 2))   }      var binaryToHexa   : String { return String(binaryToInt, radix: 16)  }  }    extension Int {      var binaryString: String { return String(self, radix: 2)  }      var hexaString  : String { return String(self, radix: 16) }      var doubleValue : Double { return Double(self) }  }    "ff".hexaToInt              // "255"  "ff".hexaToDouble           // "255.0"  "ff".hexaToBinary           // "11111111"  "255".intToHexa             // "ff"  "255".intToBinary           // "11111111"  "11111111".binaryToInt      // "255"  "11111111".binaryToDouble   // "255.0"  "11111111".binaryToHexa     // "ff"  255.binaryString            // "11111111"  255.hexaString              // "ff"  255.doubleValue             // 255.0  

Answer by jeff-ziligy for How to convert a binary to decimal in Swift?

binary is built-in to swift using 0b prefix

println( 0b11001 ) // Output: 25

Answer by Li Xinyang for How to convert a binary to decimal in Swift?

You can convert number using the following prefix to convert your number between different number format.

let decimalInteger = 17       // prefix NONE  let binaryInteger = 0b10001   // prefix 0b  let octalInteger = 0o21       // prefix 0o  let hexadecimalInteger = 0x11 // prefix 0x  

Fatal error: Call to a member function getElementsByTagName() on a non-object in D:\XAMPP INSTALLASTION\xampp\htdocs\endunpratama9i\www-stackoverflow-info-proses.php on line 72