Java: How to convert a String of Binary values to a Float and vice-versa?

Question

How do I convert the float value of 12345.12346f to a String of binary values, i.e. "0011010101010101", and vice-versa?

Solution 1

I'm not sure it is what you want, but here's a solution to have the binary representation of the IEEE 754 floating-point "double format" bit layout for a float (it is basically the memory representation of a float) :

int intBits = Float.floatToIntBits(yourFloat); 
String binary = Integer.toBinaryString(intBits);

For the reverse procedure :

int intBits = Integer.parseInt(myString, 2);
float myFloat = Float.intBitsToFloat(intBits);

Solution 2

Working sample:

class F { 
  public static void main( String ... args ) { 
    System.out.println(
          Integer.toBinaryString( 
             Float.floatToIntBits(12345.12346f)
          ) 
     );
  }
}

Output:

1000110010000001110010001111110

Solution 3

For signed Floats, use Long or BigInteger to parse the string. Casting by int causes the digit at first of 32 bits be intepreted as sign digit. procedure :

int intBits = Float.floatToIntBits(yourFloat); 
String binary = Integer.toBinaryString(intBits);

reverse procedure :

int intBits = new BigInteger(myString, 2).intValue();
// int intBits = (int) Long.parseLong(myString, 2);
float myFloat = Float.intBitsToFloat(intBits);