How i can printf result like 0.0045

Question

     I only get this 

1667785316

1667785316

1667785316

     Float32 preferredBufferSize = 0.005; // 5 millis buffer
  UInt32 size = sizeof(preferredBufferSize);


    AudioSessionGetProperty(kAudioSessionProperty_CurrentHardwareIOBufferDuration, &size,
                &preferredBufferSize);
   printf("\n%d", kAudioSessionProperty_CurrentHardwareIOBufferDuration);

If

        printf("\n%.4f", kAudioSessionProperty_CurrentHardwareIOBufferDuration);

i get 736204793259769514805539544958332881185808905380376591296729466482703872896792123284994544877461533270472921226586720994654163338779026978512060081697113376452636514975744.0000 736204793259769514805539544958332881185808905380376591296729466482703872896792123284994544877461533270472921226586720994654163338779026978512060081697113376452636514975744.0000

Answer 1

You're using an integer symbol. Use a float instead.

printf("\n%.4f", kAudioSessionProperty_CurrentHardwareIOBufferDuration);

Answer 2

printf("\n%.4f", kAudioSessionProperty_CurrentHardwareIOBufferDuration);

if you want 4 decimal place precision on a 32-bit floating point number. Drop the .4 if you want arbitrary length.