Null Character:\0
# define TAXRATE 0.015 //when your program is compiled,the value 0.015 will be substituted everywhere you have used TAXRATE.this is called a compile-time substitution.
const int MONTHS =12; //MONTHS a symbolic constant for 12
printf("*%10d*\n",pages); //* 959*
printf("*%-10d*\n",pages); //*959 *
printf("*%f*\n"); //*3852.990000*
printf("*%e*\n"); //*3.852900e+03*
printf("*%4.2f*\n"); //*3852.99*
printf("*%3.1f*\n"); //*3853.0*
printf("*%+4.2f*\n"); //*+3852.99*
printf("*%010.2f*\n"); //*0003852.99*
三种分行书写printf()的方法:printf("here is one way to print a");
printf("long string");
printf("here is another way to print a \
long string");
printf("here is the newest way to print a"
"long string"); // ansi c
the * modifier with printf() and scanf():if you have the conversion specifier %*d,the argument list should include a value for * and a value for d.
printf("the number is :%*d\n",width,number);
printf("weight= %*.*f\n",width,precision,wight);
scanf("%*d %*d %d,&n); //跳过相应的输入,将第三个输入的值赋给n