3-15.txt

C++完美演绎 经典算法 如 /* 头文件：my_Include.h */ #include <stdio.h> /* 展开C语言的内建函数指令 */ #define PI 3.141

/* 范例：3-15 */
#include <stdio.h>
void main(void)
{
  long int a;  	/* 定义变量a为long int类型 */
  short int b;  	/* 定义变量b为short int类型 */
  printf("long int = %d bytes\n", sizeof(a));  /* a占内存bytes数*/
  printf("short int = %d bytes\n", sizeof(b)); /* b占内存bytes数*/

  signed int c; 	/* 定义变量c为signed int类型   */
  unsigned int d;	/* 定义变量d为unsigned int类型 */
  printf("signed int = %d bytes\n", sizeof(c));/* c占内存bytes数 */
  printf("unsigned int = %d bytes\n", sizeof(d)); /* d占多少bytes */

  signed long int e;  	/* 定义变量e为signed long int类型   */
  unsigned long int f; 	/* 定义变量f为unsigned long int类型 */
  printf("signed long int = %d bytes\n", sizeof(e));
      /* e占内存多少bytes */
  printf("unsigned long int = %d bytes\n", sizeof(f));
      /* f占内存多少bytes */

  signed short int g;		/* 定义变量g为signed short int类型 */
  unsigned short int h;	/* 定义变量h为unsigned short int类型 */
  printf("signed short int = %d bytes\n", sizeof(g));
      /* g占内存多少bytes */
  printf("unsigned short int = %d bytes\n", sizeof(h));
      /* h占内存多少bytes */

  unsigned x; 	/* 等同于unsigned int x; */
  signed y;  	/* 等同于signed int y; */
  long z; 	/* 等同于long int z; */
  short v;  	/* 等同于 short int v; */
  printf("unsigned = %d\n", sizeof(x));	/* unsigned x占内存多少bytes */
  printf("signed = %d\n", sizeof(y)); 	/* signed y占内存多少bytes */
  printf("long = %d\n", sizeof(z));   	/* long z占内存多少bytes */
  printf("short = %d\n", sizeof(v));  	/* short v占内存多少bytes */
  /* 标识浮点数类型的方式,标识char(字符类型)的方式 */
  printf("\nunsigned char = %d bytes", sizeof(unsigned char));
  printf("\nsigned char = %d bytes", sizeof(signed char));
  printf("\nfloat = %d bytes", sizeof(float));
  printf("\ndouble = %d bytes", sizeof(double));
  printf("\nlong double = %d bytes\n", sizeof(long double));
	/* char基本数据类型 */
 	/* 定义变量ch为char类型，并设初值是字符'B' */
  char ch = 'B';
	/* 定义变量asc为char类型，并设初值是数值66，数值66在char类型代表ASCII码，也是等于字符'B' */
  char asc = 66;
  printf("\n变量ch:%c\n变量asc:%c\n", ch, asc);
	/* float基本数据类型 */
  float i = 62.2;	/* 一般基本浮点数类型，将a定义为浮点数类型 */
  float j = 38.7; 	/* 将b定义为浮点数类型 */
  float currency = 6.226E+02;  /* 将currency变量定义为浮点数类型并设初值，初值以科学符号表示 */
  printf("\nFloat i = %f", i); 	/* 使用%f浮点数各格式化符号对应到变量a */
  printf("\nFloat j = %f", j); 	/* 使用%f浮点数各格式化符号对应到变量b */
  printf("\nFloat i-j = %f", i-j);	/* 使用加减运算符做a-b */
  printf("\nFloat currency = %f", currency);
      /* 使用%f浮点数各格式化符号打印到变量currency */
  printf("\nFloat currency-(i+j)=%f", currency-(i+j));
  getchar();
}

程序执行结果 ﹕
long int = 4 bytes
short int = 2 bytes
signed int = 4 bytes
unsigned int = 4 bytes
signed long int = 4 bytes
unsigned long int = 4 bytes
signed short int = 2 bytes
unsigned short int = 2 bytes
unsigned = 4
signed = 4
long = 4
short = 2

unsigned char = 1 bytes
signed char = 1 bytes
float = 4 bytes
double = 8 bytes
long double = 10 bytes
变量ch:B
变量asc:B

Float i = 62.200001
Float j = 38.700001
Float i-j = 23.500000
Float currency = 622.599976
Float currency-(i+j)=521.699974