Rounding off a float to two decimal places

Question

I want to make a function where I shall pass a float and and integer.
The float shall have to be rounded off to a value in the integer.
Can anyone please suggest how to round off a float.
E.g.: if the float is 12.56890 and I want to round it off to 2 decimal places, then it should be 12.57.
Regards
Hawker

Answer 1

I didn't mention any datatypes like float, double.True, but that is what the question is about, so you weren't answering the question. For a change.
As I mentioned, that was just a mathematical steps to round of the floating point value. (Not in any programming languages point of view).False. You didn't mention that at all.
This is the code for that in java.So here you are mentioning datatypes and floats for the same piece of mathematics that you have already been told, with reasons, doesn't work in floating point.
which seems to be working fine
Seems to. What evidence do you have that the float actually got rounded? As opposed to got displayed as rounded? Which is not what the OP asked for.
And of course all that code seems to do is round 0.01 to two decimal places, which again is not what the OP asked for.
For any remaining fans of this 'technique', please explain the behaviour of the following code:
     public static void     main(String[] args)
          int     count = 0, errors = 0;
          for (double x = 0.0; x < 1; x += 0.0001)
               count++;
               double     d = x;
               int     scale = 2;
               double     factor = Math.pow(10, scale);
               d = Math.round(d*factor)/factor;
               if ((d % 0.01) != 0.0) // if 'd' really has been rounded this should be zero
                    System.out.println(d % 0.01);
                    errors++;
          System.out.println(count+" trials "+errors+" errors");
     }