格式化输出1.cpp

我正在学习C编程

#include<stdio.h>   /*格式化输出*/
void main()
{
	char c='a';
	int a=1234;
	float f=3.141592653589;
	double x=0.12345678987654321;
	printf("\n\t格式化输出:\n\n定义赋值: char c='a';\n");
	printf("          int a=1234;\n");
	printf("          float f=3.141592653589;\n");
	printf("          double x=0.12345678987654321;\n");
	printf("\n a=%d-------输出十进制整数\n",a);
	printf(" a=%6d-----输出6位十进制整数,左补空格\n",a);    
	printf(" a=%06d-----输出6位十进制整数,左补0\n",a);
	printf(" a=%2d-------输出实际值,a长度超过2位\n",a);
	printf(" a=%o-------输出八进制整数\n",a);
	printf(" a=%-8o---输出8位八进制整数,右补空格\n",a);
	printf(" a=%8o---输出8位八进制整数,左补空格\n",a);
	printf(" a=%-6x-----输出6位十六进制整数,右补空格\n",a);
	printf(" a=%6x-----输出6位十六进制整数,左补空格\n",a);
	printf(" a=%x--------输出十六进制整数\n",a);
	printf(" f=%f---输出浮点数,6位小数\n",f);
	printf(" f=%6.4f-----输出浮点数,总长6位,小数4位\n",f);
	printf(" x=%lf---输出长浮点数,6位小数\n",x);
	printf(" x=%18.16lf-----输出长浮点数,总长18位,小数16位\n",x);
	printf(" c=%c----------输出字符变量c的值\n",c);
	printf(" c=%d---------输出字符变量c的十进制整数值\n",c);
	printf(" c=%x---------输出字符变量c的十六进制整数值\n",c);
	printf(" 字符串=%s-------输出原字符串,总长15个字符\n","Hello,comrade!!");
	printf(" 字符串=%6.9s-------------输出原字符串前9个字符\n","Hello,comrade!!");
	printf(" 字符串=%-19.9s---输出原字符串(长15)前9个字符,总长19个字符,右补空格\n","Hello,comrade!!");
	printf(" 字符串=%19.9s---输出原字符串(长15)前9个字符,总长19个字符,左补空格\n","Hello,comrade!!");
	printf(" 字符串=%-15.10s-----输出原字符串(长15)前10个字符,总长15个字符,右补空格\n","Hello,comrade!!");
	printf(" 字符串=%15.10s-----输出原字符串(长15)前10个字符,总长15个字符,左补空格\n","Hello,comrade!!");
	printf("%-7c------why?输出单符'    ',总长7位,右补空格\n","Hello,comrade!!");   //why?
	printf("%7c------why?输出单符'    ',总长7位,左补空格\n","Hello,comrade!!");  //why?
	printf("%-7c------输出单符'H',总长7位,右补空格\n",'H');
	printf("%7c------输出单符'H',总长7位,左补空格\n",'H');
	printf("\n");

}