Difference between %d and %f?

Hi, I dont quite understand the difference between %d and %f and its usage in certain cases.

Does %d correspond to int in C and %f correspond to float?

What is the case I have to use %d instead of %f?

Answer 1

[Adam Danz]

Refer to the documentation.

%d represents signed integers (base 10).

sprintf('John is %d years old', 7)
% 'John is 7 years old'

%f represents floating point numbers.

sprintf('The first 8 dp of pi are %.8f', pi)
%  'The first 8 dp of pi are 3.14159265'

%f can also be used to represent integers by rounding floating point inputs. %d cannot be used in this way.

sprintf('Pi is rounded to %.0f', pi)
% 'Pi is rounded to 3'

sprintf('Pi is rounded to %.d', pi)
% 'Pi is rounded to 3e+00'

[JUNAID]

I didn't understand.

Answer 2

[Steven Lord]

If you want to print integer values, you probably want to use %d.

If you want to print non-integer values, you probably want to use %f.

While you can use %f to print integer values (as per the second line of code below) if you try to use %d to print non-integer values it will actually switch to a different specifier (%e I believe, as per the note in the Notable Behavior of Conversions with Formatting Operators section of the description of the formatSpec input argument on the fprintf documentation page.)

fprintf("This uses the %%d format specifier: %d\n", 42)

This uses the %d format specifier: 42

fprintf("This uses the %%f format specifier: %f\n", 42)

This uses the %f format specifier: 42.000000

fprintf("This uses the %%d format specifier: %d\n", pi) 

This uses the %d format specifier: 3.141593e+00

fprintf("This uses the %%f format specifier: %f\n", pi) 

This uses the %f format specifier: 3.141593