printf not working for float - how can I convert float on consloe just like integers?

[tvnaidu]

I am doing floating point calculation inside C function, with debugger I can see float values in single step, if I want to print them on console, I am using printf, but printf not working for flaot, how can I convert them to int and print on console using printf. I tried to print with %d, but float, but not printing, any idea?.
Thanks.

[shabinesh]

if you want to print the floating point value to the console you can use %f . if you want to convert floating point to integer just typecast it. I wonder if you were expecting this answer.

[tvnaidu]

somehow printf library not printing if I use %f, but if I typecast to int, then it roundsup but I am loosing that truncated value.

[Banfa]

Perhaps you should post the code you are using to print, including data types of variables being printed.

Additionally it would help to know what platform you are working on, some embedded platforms have options to leaving floating point support out of printf.

[donbock]

@tvnaidu
Do you mean

• nothing at all is printed;
• surrounding text is printed but the floating point value isn't;
• the wrong value is printed.

We can't help you if we don't know what is happening.

I second Banfa's request, we will have a better idea what is going on if you gave us a code snippet -- just the printf call and the types of all variables used in it.

[RRick]

Are you using a double or float to declare the real number? They are different sizes in C/C++.

In the past, I found that %f would work for float but not for double. For double I had to use %lf.

[Banfa]

@RRick
No that's wrong, in the absence of a prototyped parameter (such as the printf varidac function declaration) floats are automatically promoted to double for parameter passing (same as shorts and chars are promoted to int). %f is for double, %Lf is for long double.

In this instance printf and scanf format specifiers differ because for scanf %f is for float, %lf for double and %Lf for long double.

[tvnaidu]

Thanks. I am using float only, not double.

[donbock]

Are you still having trouble with this? If so, please post a relevant code snippet that shows your call to printf and the types of all arguments passed to printf; and describe the result you see and how it differs from what you expect.

[tvnaidu]

Thanks for help. actually I moved all floats to int, earlier I thought I need float, but most of ADC readings are integers, then when I double and do average and do square-root also it is integers.