The thing about printf.

1. Print memory address

#include <stdio.h>int main () {int a;printf ("%p\n", &a);   %p Print address, the active prefix 00printf ("0x%x\n", &a); %x prints return 0 in hexadecimal;}

Output Result:

0012ff44
0x12ff44

2, printf. sprintf,snprintf

Prototype:

int printf (const char *format, ...); int sprintf (char *str, const char *format, ...); int snprintf (char *str, size_t size, const char *format, ...);

The sprintf string is formatted into the target string.

snprintf copies the string to a maximum of size-1 characters to the target string.

#include <stdio.h>int main () {char A[20];char *p = "Hello,iot_xiaohe"; sprintf (A, "%s", p);p rintf ("sprintf A is:%s\n ", a); snprintf (a,10,"%s ", p);p rintf (" snprintf A is:%s\n ", a); return 0;}

Output Result:

sprintf a Is:hello,iot_xiaohe
snprintf a Is:hello,iot

The thing about printf.