C_使用switch语句
源码:
# include <stdio.h>
int main()
{
int num;
/* 下面定义的各变量,分别代表个位,十位,百位,千位,万位,十万位以及位数 */
int indiv, ten, hundred, thousand;
int ten_thousand, hundred_thousand, place;
printf("请输入一个整数(0~999999):");
scanf("%d", &num);
/* 判断变量num的位数 */
if(num > 99999)
place = 6;
else if(num > 9999)
place = 5;
else if(num > 999)
place = 4;
else if(num > 99)
place = 3;
else if(num > 9)
place = 2;
else
place = 1;
printf("place = %d\n", place);
printf("每位数字为:");
/* 求出num在各位上的值 */
hundred_thousand = num/100000;
ten_thousand = (num - hundred_thousand*100000)/10000;
thousand = (num - hundred_thousand*100000 - ten_thousand*10000)/1000;
hundred = (num - hundred_thousand*100000 - ten_thousand*10000
- thousand*1000)/100;
ten = (num - hundred_thousand*100000 - ten_thousand*10000
- thousand*1000 - hundred*100)/10;
indiv = num - hundred_thousand*100000 - ten_thousand*10000
- thousand*1000 - hundred*100 - ten*10;
/* 判断变
相关文档:
例:#define NELE(a) (sizeof(a) / sizeof(a[0]))
int main() {
char str[] = {'E', 'M', 'C'};
for (int d=-1; d<=(NELE(str)-2);d++)
printf("%c",str[d+1]);
return 0;
}
判断printf()输出的是什么,结果可能出乎意料,什么也没有输出,原因呢?原因 ......
提出问题:
回调函数是基于C编程的Windows SDK的技术,不是针对C++的,程序员可以将一个C函数直接作为回调函数,但是如果试图直接使用C++的成员函数作为回调函数将发生错误,甚至编译就不能通过。
分析原因:
普通的C++成员函数都隐含了一个传递函数作为参数,亦即“this”指针,C++通过传递一个指向自身的指 ......
源码:
# include <stdio.h>
int main()
{
/* 换行符'\n',用于输出换行 */
printf("How are you?\n");
printf("I am fine.\n\n");
/* 横向跳格符'\t',使跳到下一个输出区 */
  ......
源码:
# include <stdio.h>
int main()
{
int i, j, k;
int m, n, p;
i = 8;
j = 10;
k = 12;
/* 自增在操作数之前 */
  ......
源码:
# include <stdio.h>
int main()
{
/* 定义字符型变量,并给它们付初值 */
char c1, c2, c3, c4, c5, c6, c7;
c1 = 'C';
c2 = 'h';
c3 = 'i';
c4 = 'n';
& ......