各数据类型常用的stdio格式

紧接上一篇，贴一下各种数据类型的stdio格式，这东西其实挺麻烦记的

数据类型名称	字节数	别名	stdio基本说明格式
int	*	signed, signed int	%d, %i
unsigned int	*	unsigned	%u, %o, %x, %X
__int8	1	char, signed char	%hhd
__int16	2	short, short int, signed short int	%hd
__int32	4	long, long int, signed long int	%ld, (%I32d)
__int64	8	long long, long long int, signed long long int	%lld, (%I64d)
bool	1
char	1	signed char, (__int8)	%hhd, %c
unsigned char	1		%hhu, %hho, %hhx, %hhX
short	2	short int, signed short int, (__int16)	%hd
unsigned short	2	unsigned short int	%hu, %ho, %hx, %hX
long	4	long int, signed long int, (__int32)	%ld, (%I32d)
unsigned long	4	unsigned long int	%lu, (%I32u), %lo, %lx, %lX
long long	8	long long int, signed long long int, (__int64)	%lld, (%I64d)
unsigned long long	8	unsigned long long int	%llu, (%I64u), %llo, %llx, %llX
enum	*
float	4	无	%f, %e, %E, %g, %G
double	8	无	%lf, %le, %lE, %lg, %lG
long double	*	无	%llf, %lle, %llE, %llg, %llG
wchar_t	2	__wchar_t
char[]	*		%s
void *	*		%p

  

 

 

说明：

1、上述基本类型说明：

（1）、对于整数，d（i）代表有符号，u代表无符号，h和l分别用来进一步说明字长，防止出错，32位和64位整数还提供了I32和I64这样的说明格式；o和x（X）分别是八进制和十六进制输出，x和X只是字母大小写的区别，不过，形如%o%x%X这样的输出是没有前缀的，补充前缀的格式见下文；

（2）、对于浮点数，f是浮点输出，e（E）是科学计数法输出，后者同样是幂符号的大小写区别，l用来增补长度；g（E）则是取f和e（E）中的较短者输出；

2、格式标识

'正整数': 设置输出场宽，当输出实际长度大于设置场宽，则忽略该设置

'-'和'0': 无'-'和'0'时结果右对齐，左端补充空格；设置'-'时结果左对齐，右端补充空格；（对整数，还可以设置'0'表示右对齐，左端补充'0'）

'+'和' ': 设置数字符号格式，'+'表示正负号都输出，' '表示只输出符号，不输出正号

'#': 设置几种数字的格式。对o：输出前缀0；对x（X）：输出前缀0x（0X）；对g（G）：输出尾随0（默认是不输出尾随0的）；对f：保证输出小数点（即使浮点后没有数字）

3、精度设置

'.正整数': 对f的设置，没有此设置时默认输出6位，注意：有舍入而非截去

 

总结：格式标志（如果可用）和精度设置（如果可用）插入在百分号和格式说明中间，即（下面用竖杆隔开）：

"%|格式标志|精度设置|格式说明"

简单举一个例子：printf("%-12.8lf/n", doubleVar);

 

 

 

测试的时候发现了一些小问题：比如long double的实际精度确实没有想象的那么大//#include <windows.h> #include <iostream> #include <fstream> #include <cstdio> #include <cmath> #include <cstdlib> #include <cstring> #include <algorithm> using namespace std; //LARGE_INTEGER _lTemp; //LONGLONG _dFreq, _bTime, _eTime; //double _uTime; int main(){ // freopen("in.txt", "r", stdin); //重定向输入 freopen("out.txt", "w", stdout);//重定向输出 // QueryPerformanceFrequency(&_lTemp); //获取运算频率 // _dFreq = _lTemp.QuadPart; //获取运算频率大整数 // QueryPerformanceCounter(&_lTemp); //获取开始时间 // _bTime = _lTemp.QuadPart; //获取开始时间大整数 int intVar = -4541585; unsigned int unintVar = 36215; __int8 int8Var = 15; __int16 int16Var = 1255; __int32 int32Var = 2365644L; __int64 int64Var = 154481554545LL; char charVar = 'C'; unsigned char uncharVar = 154; short shortVar = -15444; unsigned short unshortVar = 12545; long longVar = -125488L; unsigned long unlongVar = 564588L; long long longlongVar = -153465554LL; unsigned long long unlonglongVar = 8481585LL; float floatVar = 3.1415f; double doubleVar = -3.141592658; long double longdoubleVar = 75.5455515115455184l; char strVar[20] = "This is a string."; // printf("Test 1:/n"); printf(" int: %d %i %u/n", intVar, intVar, unintVar); printf(" __int: %hhd %hd %ld %lld/n", int8Var, int16Var, int32Var, int64Var); printf(" char: %c/n", charVar); printf(" signed: %hhd %hd %ld %lld/n", charVar, shortVar, longVar, longlongVar); printf("unsigned: %hhu %hu %lu %llu/n", uncharVar, unshortVar, unlongVar, unlonglongVar); printf(" octal: %o %hho %ho %lo %llo/n", unintVar, uncharVar, unshortVar, unlongVar, unlonglongVar); printf(" hex: %x %hhX %hx %lX %llx/n", unintVar, uncharVar, unshortVar, unlongVar, unlonglongVar); printf(" float: %f %lf %llf/n", floatVar, doubleVar, longdoubleVar); printf(" science: %e %lE %lle/n", floatVar, doubleVar, longdoubleVar); printf(" string: %s/n", strVar); // printf("/nTest 2:/n"); printf("%30s/n%-30sEND/n", strVar, strVar); printf("%015d/n", intVar); printf("%+hhd % hhd/n", int8Var, int8Var); printf("%#o %#X/n", unintVar, unintVar); // printf("/nTest 3:/n"); printf("%.3f %.12lf %.18llf/n", floatVar, doubleVar, longdoubleVar); // printf("/nTest 4:/n"); printf("%+015hhd/n", int8Var); printf("%-12.8lfEND/n", doubleVar); // QueryPerformanceCounter(&_lTemp); //获取终止时间 // _eTime = _lTemp.QuadPart; //获取终止时间大整数 // _uTime = 1000 * double(_eTime - _bTime) / double(_dFreq); //计算总耗时，转化成ms // printf("Time used: %012.3f ms/n", _uTime); //输出总耗时，单位是ms // fclose(stdin); //关闭文件 fclose(stdout); //关闭文件 return 0; } /* Test 1: int: -4541585 -4541585 36215 __int: 15 1255 2365644 154481554545 char: C signed: 67 -15444 -125488 -153465554 unsigned: 154 12545 564588 8481585 octal: 106567 232 30401 2116554 40265461 hex: 8d77 9A 3101 89D6C 816b31 float: 3.141500 -3.141593 75.545552 science: 3.141500e+000 -3.141593E+000 7.554555e+001 string: This is a string. Test 2: This is a string. This is a string. END -00000004541585 +15 15 0106567 0X8D77 Test 3: 3.141 -3.141592658000 75.545551511545511000 Test 4: +00000000000015 -3.14159266 END */

声明： 水平有限，可能有错漏的地方，欢迎批评指正