printf()打印十六进制，八进制，十进制，二进制数字段宽度

#include <stdio.h>


int main( void )
{
    float d1 = 10000.123;
    int n, f;
    char *m1 = "Binary";
    char *m2 = "Decimal";
    char *m3 = "Octal";
    char *m4 = "Hexadecimal";


    puts("Outputting a number with different field widths./n");

    printf("%5f/n", d1);
    printf("%10f/n", d1);
    printf("%15f/n", d1);
    printf("%20f/n", d1);
    printf("%25f/n", d1);

    fflush(stdin);

    puts("/nUse the * field width specifier to obtain field width");
    puts("from a variable in the argument list./n");

    for (n=5;n<=25; n+=5)
        printf("%*f/n", n, d1);

    puts("/n Press Enter to continue...");
    fflush(stdin);
    getchar();

    puts("/nInclude leading zeros./n");

    printf("%05f/n", d1);
    printf("%010f/n", d1);
    printf("%015f/n", d1);
    printf("%020f/n", d1);
    printf("%025f/n", d1);

    fflush(stdin);

    puts("/nDisplay in octal, decimal, and hexadecimal.");
    puts("Use # to precede octal and hex output with 0 and 0X.");
    puts("Use - to left-justify each value in its field.");

    printf("%-15s%-15s%-15s", m2, m3, m4);

    for (n = 1;n< 20; n++)
        printf("/n%-15d%-#15o%-#15X", n, n, n);

    fflush(stdin);

    puts("/n/nUse the %n conversion command to count characters./n");

    printf("%s%s%s%s%n", m1, m2, m3, m4, &n);

    printf("/n/nThe last printf() output %d characters./n", n);

    return 0;
}