关于printf

printf函数的一些使用方法。

#include <stdio.h>

#define SHORT_MAX 0x7FFF
#define INT_MAX 0x7FFFFFFF
#define LONG_MAX 0x7FFFFFFFFFFFFFFF

void print_d()
{
    int i = 10;
    int j = -10;

    printf("|%.5d|\n", i);
    printf("|%05d|\n", i);

    printf("|%.5d|\n", j);
    printf("|%05d|\n", j);

    printf("|%5d|\n", i);
    printf("|%-5d|\n", i);

    printf("|%+d|\n", i);

    printf("|%*.*d|\n", 5, 3, i);

    printf("%hd\n", SHORT_MAX);
    printf("%d\n", INT_MAX);
    printf("%ld\n", LONG_MAX);

    printf("|% d|\n", i);
    printf("|% d|\n", j);

    printf("\n");
}

void print_s()
{
    char* str = "abcde";

    printf("|%5.3s|\n", str);
    printf("|%-5.3s|\n", str);

    printf("|%*.*s|\n", 5, 3, str);

    printf("\n");
}

void print_f()
{
    float f = 11.23456;
    double df = 11.23456;
    long double ldf = 99999999999998.4111111111;

    printf("|%f|\n", f);
    printf("|%f|\n", df);

    printf("|%7.3f|\n", f);
    printf("|%7.3f|\n", df);
    printf("|%*.*f|\n", 7, 3, f);
    printf("|%*.*f|\n", 7, 3, df);

    printf("|%'Lf|\n", ldf);
    printf("|%'.4Lf|\n", ldf);

    printf("%e\n", df);
    printf("%g\n", df);

    printf("\n");
}

void print_o()
{
    int i = 10000;

    printf("%x\n", i);
    printf("%o\n", i);

    printf("%#x\n", i);
    printf("%#o\n", i);

    printf("\n");
}

int main(int argc, char *argv[])
{
    print_d();

    print_f();

    print_s();

    print_o();

    return 0;
}

下面是执行结果

|00010|
|00010|
|-00010|
|-0010|
|   10|
|10   |
|+10|
|  010|
32767
2147483647
9223372036854775807
| 10|
|-10|

|11.234560|
|11.234560|
| 11.235|
| 11.235|
| 11.235|
| 11.235|
|99999999999998.406250|
|99999999999998.4062|
1.123456e+01
11.2346

|  abc|
|abc  |
|  abc|

2710
23420
0x2710
023420