negative number representation in binary code example

Example 1: decimal to binary

//Java Solution for Decimal To Binary Conversion

import java.util.*;
public class DecimalToBinary {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner sc = new Scanner(System.in);
		int dec = sc.nextInt();
		StringBuffer sb = new StringBuffer();
		while(dec!=0)
		{
			sb.append(dec%2);
			dec=dec/2;
		}
		System.out.println(sb.reverse());
		
	}

}

Example 2: converting float to binary 16

import struct
#################### bin32 ################################
# import bitstring
# f1 = bitstring.BitArray(float=0.456789, length=32)
# # f1 = bitstring.BitArray(float=0.456789, length=16)
# print(f1.bin)
# print("0011011101001111")
#################### bin32 ################################

def convertFloatToBin16(x):
    k = struct.pack('>e', x)
    z = ''.join(format(i, '08b') for i in k)
    return str(z)

print(convertFloatToBin16(0.9945678))