Convert hexadecimal to binary - binary

Question

I am converting the hexadecimal number 0XA85D10 to binary. However, I am told you can convert this number without using paper or a calculator.
Is this possible?
Thanks

Answer 1

The easiest way to convert from hex to binary is to split each digit in the hex into an 4 digit binary number. (i.e. D matches to 1110)
Using your example
A 8 5 D 1 0
1010 1000 0101 1110 0001 0000

Answer 2

Yes. It is possible. One hexadecimal digit is exactly four binary digits.
A = 1010
8 = 1000
...and so on.
If the digit is greater or equal to 8, then subtract 8 from the digit the first binary digit is 1, otherwise it is zero.
If the digit is now greater or equal to 4, then subtract 4 and the next digit out is 1, otherwise the next digit out is 0.
If the digit is now greater or equal to 2, then subtract 2 and the next digit out is 1, otherwise the next digit out is 0.
Whatever is left, 0 or 1, is the remaining digit.

Answer 3

Easily. Each digit in a hex number translates to 4 digits in a binary number, so you only need to know the binary numbers from 0 to f, or 0000 to 1111.
As an example:
0xc3e2
c = 12 decimal = 1100
3 = 0011
e = 14 decimal = 1110
2 = 0010
Then just string them together.
0xc3e2 = 1100001111100010 binary

Answer 4

You can convert Hexadecimal to Binary using the following (Hex -> Binary):
0 = 0000
1 = 0001
2 = 0010
3 = 0011
4 = 0100
5 = 0101
6 = 0110
7 = 0111
8 = 1000
9 = 1001
A = 1010
B = 1011
C = 1100
D = 1101
E = 1110
F = 1111
Hope this helps!

Answer 5

public with sharing class HexToBin {
private String code;
public String result;
Map<String, String> hexToBinMap = new Map<String, String>{'0'=>'0000','1'=>'0001','2'=>'0010','3'=>'0011','4'=>'0100','5'=>'0101','6'=>'0110','7'=>'0111','8'=>'1000','9'=>'1001','A'=>'1010','B'=>'1011','C'=>'1100','D'=>'1101','E'=>'1110','F'=>'1111'};
public HexToBin(String code) {
this.code = code;
result = getResult(code);
}
private String hexToBin(String hex){
if(hex.length()==1){
return hexToBinMap.get(hex);
}
return '';
}
private String getResult (String code) {
String res ='';
for(Integer i=0; i<code.length(); i++){
res = res + hexToBin(code.substring(i,i+1));
}
return res;
}
}