CODEWITHSUNDEEP
androidinthex
masmic
masmic

Reputation: 3564

android int to hex converting

I have to convert an int to an hex value. This is for example the int value:

int_value = -13516;

To convert to a hex value i do:

hex_value = Integer.toHexString(int_value);

The value that I should get is : -34CC (I don't know if i should make it positive).

The thing is that doing the conversion that way, the value that I get is: ffff cb34

Can't I use this function to make this conversion?

Upvotes: 22

Views: 49618

Answers (7)

Nebobrod
Nebobrod

Reputation: 13

The question has hidden mistake: if we are talking about four Hex digits that doesn't mean int (4 bytes or 8 Hex digits) but short in Java.

If we are talking about int we must keep 8 Hex digits. The upper example gives wrong transformation with big numbers of negative int.

    // Convert int to Hex String
    int value = -1878724255; //-13516; //

    String hexString = String.format("%08X", value);
    System.out.println("1: " + hexString);

    // this is wrong for an int
    int value2 = (value < 0) ? value + 65536 : value;
    System.out.println("2: " + Integer.toString(value2, 16));

    // Correct way to handle negative values of int is adding 2^32 (4294967296)
    long unsignedValue = value & 0xFFFFFFFFL;
    System.out.println("3: " + Long.toString(unsignedValue, 16));

the result:

1: 9004F161
2: -6ffa0e9f
3: 9004f161

Upvotes: 0

Pablo C. Garc&#237;a
Pablo C. Garc&#237;a

Reputation: 22394

String.format("#%06X", (0xFFFFFF & colorYellow));

Output: #FFC107

Upvotes: 5

arnefm
arnefm

Reputation: 1008

Documentation says Integer.toHexString returns the hexadecimal representation of the int as an unsigned value.

I believe Integer.toString(value, 16) will accomplish what you want.

Upvotes: 42

Abhilash
Abhilash

Reputation: 507

I don't think the above answers would give you the exact value for the signed bits. For example the value of 11 is 0B but the value of -11 would be F5 and not -B since 2's complement gets into the game to solve this i have modified the above answer 

int int_value = -11;
 String hex_value = int_value < 0
                           ? Integer.toHexString(int_value+65536) :    Integer.toHexString(int_value);
 String shortHexString = hex_value.substring(2);

where, 65536 is 2^16 now you can get the expected results . Happy coding :)

  • List item

Upvotes: 1

Kurt Huwig
Kurt Huwig

Reputation: 1013

Both Integer.toHexString, as well as String.format("%x") do not support signs. To solve the problem, you can use a ternary expression:

    int int_value = -13516;
    String hex_value = int_value < 0
                       ? "-" + Integer.toHexString(-int_value)
                       : Integer.toHexString(int_value);

Upvotes: 3

VM4
VM4

Reputation: 6501

public static int convert(int n) {
  return Integer.valueOf(String.valueOf(n), 16);
}
 // in onstart:
 Log.v("TAG", convert(20) + "");  // 32
 Log.v("TAG", convert(54) + "");  // 84

From: Java Convert integer to hex integer

Upvotes: 3

mdDroid
mdDroid

Reputation: 3195

Go through following code for Integer to hex and Hex to integer Conversion

public class MainActivity extends Activity {

int number;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    number = 678668;
    Log.i("ACT", "Integer Number  " + number);

    /**
     * Code for convert integer number to hex number. two mwthods.
     */
    Log.i("ACT", String.format("#%x", number)); // use lower case x for
                                                // lowercase hex
    Log.i("ACT", "#" + Integer.toHexString(number));

    /**
     * Code for convert hex number to integer number
     */
    String hex = Integer.toHexString(number).replace("/^#/", "");
    int intValue = Integer.parseInt(hex, 16);

    Log.i("ACT", "Integer Number  " + intValue);
   }

}

Upvotes: 2

Related Questions