Convert Double to Binary representation?

Question

I tried to convert a double to its binary representation, but using this Long.toBinaryString(Double.doubleToRawLongBits(d)) doesn\'t help, since I have large nu

Answer 1

You may want to process whole and fractional part :

public String toBinary(double d, int precision) {
    long wholePart = (long) d;
    return wholeToBinary(wholePart) + '.' + fractionalToBinary(d - wholePart, precision);
}

private String wholeToBinary(long l) {
    return Long.toBinaryString(l);
}

private String fractionalToBinary(double num, int precision) {
    StringBuilder binary = new StringBuilder();
    while (num > 0 && binary.length() < precision) {
        double r = num * 2;
        if (r >= 1) {
            binary.append(1);
            num = r - 1;
        } else {
            binary.append(0);
            num = r;
        }
    }
    return binary.toString();
}