How to print double precision float number in C language?

Specify "lf" format

/*
Example:print double type in C language
*/
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>
#include <stdbool.h>
#include <errno.h>
#include <unistd.h>

int main() {
  double a = 12.34;
  printf("%lf",a);
  return 0;
}