====== How to convert data type X into type Y in Java ======

**The examples below show how to convert between different data types in Java. This is useful if you write your own plugins.**

===== integer to String : =====

  int i = 42; \\ String str = Integer.toString(i);

or

  String str = "" + i; 

===== double to String : =====

   String str = Double.toString(d);

or (in ImageJ only):

   String str1 = IJ.d2s(d, n);  // n (0...9) digits to the right of the decimal point
   String str2 = IJ.d2s(d);     // 2 digits to the right of the decimal point

===== long to String : =====

   String str = Long.toString(l);

===== float to String : =====

   String str = Float.toString(f);

===== String to integer : =====

   str = "25";\\  int i = Integer.valueOf(str).intValue();

or

   int i = Integer.parseInt(str);

===== String to double : =====

   double d = Double.valueOf(str).doubleValue();

or (in ImageJ only):\\

   double d = Tools.parseDouble(str, defaultValue);\\     // results in defaultValue if the string str results in no valid number

===== String to long : =====

   long l = Long.valueOf(str).longValue();

or

   long l = Long.parseLong(str);

===== String to float : =====

   float f = Float.valueOf(str).floatValue();

===== decimal to binary : =====

   int i = 42;\\  String binstr = Integer.toBinaryString(i);

===== decimal to hexadecimal : =====

   int i = 42;\\  String hexstr = Integer.toString(i, 16);

or

    String hexstr = Integer.toHexString(i);

or (with leading zeroes and uppercase)

<code java>
   public class Hex {
      public static void main(String args[]){
          int i = 42;
          System.out.print
              (Integer.toHexString( 0x10000 | i).substring(1).toUpperCase());
      }
  }
</code>

===== Color to hexadecimal =====

(ImageJ only)

   String str = Tools.c2hex(myColor);  // results in "#rrggbb", e.g., "#FF0000" for red

===== hexadecimal (String) to integer : =====

   int i = Integer.valueOf("B8DA3", 16).intValue();

or

   int i = Integer.parseInt("B8DA3", 16);

===== ASCII code to String: =====

   int i = 64;\\  String aChar = new Character((char)i).toString();

===== integer to ASCII code (byte): =====

   char c = 'A';\\  int i = (int) c; // i will have the value 65 decimal

===== To extract ASCII codes from a String: =====

<code java>
  String test = "ABCD";
  for ( int i = 0; i < test.length(); ++i ) {
      char c = test.charAt( i );
      int i = (int) c;
      System.out.println(i);
 }
</code>

===== integer to boolean: =====

   b = (i != 0);

===== boolean to integer: =====

   i = (b)?1:0;

===== float to double =====

   float f = (float)d;

For arrays (in ImageJ only):\\

   float[] fArray = Tools.toFloat(dArray);

===== double to float =====

   double d = f;  //no explicit typecast needed

For arrays (in ImageJ only):\\

   double[] dArray = Tools.toDouble(fArray);

===== To catch illegal number conversions: =====

Try using the try/catch mechanism:

<code java>
  try{
      i = Integer.parseInt(aString);
     }
  catch(NumberFormatException e) {
  }
</code>