hexadecimal 1 to float 1 - Compare the float 1 with a predefined float 2 - If the float 1 and float 2 are the same - Print hexadecimal 2 I want to input a hexadecimal data from cool terminal say like (05 00 02 03 00 04 00 E5) And convert the data to a float value say 45.3. Now that I have to preassign a float value say 45.3 in my program so that I can compare the converted float value with the preassigned float value. If the two values match I need to print another hexadecimal value i.e( 05 03 00 01 00 02 04 4F).

I have managed to do the conversion of hexadecimal to float. Can someone please help me in comparing the two float values?
Comparing floating point values is notoriously difficult. This is because floating point is only an approximation.

You should first define an error margin - a value which is how close together the two values need to be before you consider them to be the same.

For example 1.000000 and 1.000001 could be considered to be the same value in many circumstances.

The simplest method is to just subtract one value from the other, take the absolute value of the result, and see if it is below the error margin.

bool almost(float a, float b, float margin) {
  float diff = fabs(a - b);
  return (diff &lt; margin);
}