printf()格式各种数据格式，整数，浮点数，字符串，字符，指针

#include <stdio.h>

int main (void)
{
    char            c = 'A';
    char            s[] = abcdefghijklmnopqrstuvwxyz;
    int             i = 999;
    short int       j = 17;
    unsigned int    u = 0xf123U;
    long int        l = 12312L;
    long long int   L = 0x1234567812345678LL;
    float           f = 12.978F;
    double          d = -12.3456;
    char            *cp = &c;
    int             *ip = &i;
    int             c1, c2;

    printf (Integers:\n);
    printf (%i %o %x %u\n, i ,i ,i, i);
    printf (%x %X %#x %#X\n, i, i, i, i);
    printf (%+i % i %07i %.7i\n, i, i, i, i);
    printf (%i %o %x %u\n, j ,j ,j, j);
    printf (%i %o %x %u\n, u ,u ,u, u);
    printf (%ld %lo %lx %lu\n, l ,l ,l, l);
    printf (%lli %llo %llx %llu\n, L ,L ,L, L);

    printf (\nFloats and Doubles:\n);
    printf (%f %e %g\n, f, f, f);
    printf (%.2f %.2e\n, f, f);
    printf (%.0f %.0e\n, f, f);
    printf (%7.2f %7.2e\n, f ,f);
    printf (%f %e %g\n, d ,d ,d);
    printf (%.*f\n, 3 ,d);
    printf (%*.*f\n, 8 ,2 ,d);

    printf (\nCharacters:\n);
    printf (%c\n, c);
    printf (%3c%3c\n, c, c);
    printf (%x\n, c);

    printf (\nStrings:\n);
    printf (%s\n, s);
    printf (%.5s\n, s);
    printf (%30s\n, s);
    printf (%20.5s\n, s);
    printf (%-20.5s\n, s);

    printf (\nPointers:\n);
    printf (%p  %p\n\n,  ip,  cp);

    printf (This%n is fun.%n\n, &c1, &c2);
    printf (c1 = %i, c2 = %i\n, c1, c2);

    return 0;
}