Converting a String to a float requires that you first convert the String to a Float object, then convert the Float object to a float data type (Float is an object, while float is a primitive data type).

public class s2f {

   public static void main (String[] args) {

      // String s = "fred";    // do this if you want an exception

      String s = "100.00";

      try {
         float f = Float.valueOf(s.trim()).floatValue();
         System.out.println("float f = " + f);
      } catch (NumberFormatException nfe) {
         System.out.println("NumberFormatException: " + nfe.getMessage());
      }

   }

}

Other notes

• Float.toString(float f) is used to convert in the other direction, from a float to a String.