numerical conversion methods..

i was looking for any methods in Math package that can convert any number such as [DECIMAL-OCTAL],
[BINARY-OCTAL], [HEXA-OCTAL], [BINARY-HEXA], ETC.. (my proffesor told me,) but i cant find any of it,

are there any methods such like that? or should i define my own class to perform this tasks?

Technically, it only matters on displaying them, or in the actual code, since when the program is running, everything is in binary. To enter a hex number add the 0x to the front of the number. Unfortunately, I don't know what to put to enter in as binary or octal, but I do know decimal has no prefix :)

In the printf function, I believe if you do "%0xd", it should print out the value as a hex, but i'm not positive.

How about this:

Code :

---

        System.out.println(Integer.toHexString(195012));
        System.out.println(Integer.toBinaryString(195012));
        System.out.println(Integer.toOctalString(195012));

---

Expected output would be:

Quote:

---

2f9c4
101111100111000100
574704

---

// Json

Damn! thats it!!! that's what i've been looking for! tnx sir JSon!!!! your really awesome!
i never knew that those methods were in Integer class..I thought it was in Math. Im using netbeans but i didnt notice all of those methods when everytime im using that class
\m/ \m/ \m/ \m/ \m/ \m/ \m/ \m/ \m/ \m/ \m/ \m/ \m/

my question is, regarding with OCTAL conversion.. why is it converted into String?
(i understand a liitle bit with hexa and binary) ..

and how could i reverse those methods?

if i input

Code :

---

10001110011

---

and i want it to convert into a Decimal? or
if i input

Code :

---

CABACABACABA

---

and i want it to convert into a Decimal?


hmm.

You'll have some trouble converting the second number to an integer... it's longer than 4 bytes :P

Binary String to Decimal int:

Code :

---

public static int binaryToDecimal(String num)
{
     int sum = 0;
     for (int i = 0; i <num.length(); i++)
     {
          sum += Integer.parseInt(""+num.charAt(i))*Math.pow(2,num.length()-1-i);
     }
     return sum;
}

---

Hex works basically the same way, except you have to figure out how to get the value of the number at each digit differently because parseInt doesn't recognize A-F as 10-15 :P

Ok, let me extend my first example.

Code :

---

        System.out.println("195012 hex: " + Integer.toHexString(195012));
        System.out.println("195012 binary: " + Integer.toBinaryString(195012));
        System.out.println("195012 octal: " + Integer.toOctalString(195012));
        System.out.println("From hex: " + Integer.decode("#2f9c4"));
        System.out.println("From binary: " + Integer.parseInt("101111100111000100", 2));
        System.out.println("From octal: " + Integer.decode("0574704"));

---

Output:

Quote:

---

195012 hex: 2f9c4
195012 binary: 101111100111000100
195012 octal: 574704
From hex: 195012
From binary: 195012
From octal: 195012

---

// Json

WOW TNX AGAIN SIR JSON!! \m/

TNX A LOT!!

ahh so thats the purpose of the .decode() method of Integer Class... tnx again!! \m/

but why .parseInt in binary?

Code :

---

System.out.println("From binary: " + Integer.parseInt("101111100111000100", 2));

---

Because there does not appear to be a decode for the binary number.

// Json

You could also have used parseInt("12345670",8) for octal numbers.

Indeed :)

// Json