sprintf函数使用详解

tips:
1.函数包含在stdio.h文件中，使用#include<stdio.h>
2.函数声明：int sprintf( char *buffer, const char *format , [argument,...] );
3.主要功能是根据char *format定义格式输出到字符串缓冲区buffer

sprintf主要是依靠控制格式的字符串const char *format 来完成灵活的写入
format的用法跟printf函数的一样，下面介绍printf的format结构
format的结构 %[flags][width][.precision][length]specifier
1.specifier

specifier	Output	Example
d or i	Signed decimal integer	392
u	Unsigned decimal integer	7235
o	Unsigned octal	610
x	Unsigned hexadecimal integer	7fa
X	Unsigned hexadecimal integer (uppercase)	7FA
f	Decimal floating point, lowercase	392.65
F	Decimal floating point, uppercase	392.65
e	Scientific notation (mantissa/exponent), lowercase	3.9265e+2
E	Scientific notation (mantissa/exponent), uppercase	3.9265E+2
g	Use the shortest representation: %e or %f	392.65
G	Use the shortest representation: %E or %F	392.65
a	Hexadecimal floating point, lowercase	-0xc.90fep-2
A	Hexadecimal floating point, uppercase	-0XC.90FEP-2
c	Character	a
s	String of characters	sample
p	Pointer address	b8000000
n	Nothing printed. The corresponding argument must be a pointer to a signed int.The number of characters written so far is stored in the pointed location.
%	A % followed by another % character will write a single % to the stream.	%

2.flags

flags	description
-	Left-justify within the given field width; Right

+ Forces to preceed the result with a plus or minus sign (+ or -) even for positive numbers. By default, only negative numbers are preceded with a - sign.
(space) If no sign is going to be written, a blank space is inserted before the value.
Used with o, x or X specifiers the value is preceeded with 0, 0x or 0X respectively for values different than zero.
Used with a, A, e, E, f, F, g or G it forces the written output to contain a decimal point even if no more digits follow. By default, if no digits follow, no decimal point is written.
0 Left-pads the number with zeroes (0) instead of spaces when padding is specified (see width sub-specifier).