1.编写一个程序,读取键盘输入,直到遇到@符号为止,并回显输入(数字除外),
同时将大写字符转换为小写字符,将小写字符转换为大写(别忘了cctype函数系列)
#include <iostream>
int main()
{
using namespace std;
char ch;
cout << "Enter characters:(enter @ to stop)" << endl;
while ((ch = cin.get()) != '@') {
if (isupper(ch))
ch = tolower(ch);
else if(islower(ch))
{
ch = toupper(ch);
}
if(!isdigit(ch))
{
cout << ch << endl;
}
}
return 0;
}
2.编写一个程序,最多将10个donation值读入一个double数组中
(如果你愿意,也可以使用模板类array)。
程序遇到非数字输入时将结束输入,并报告这些数字的平均值以及数组中有多少个数字大于平均值。
#include <iostream>
const int num = 10;
int main() {
using namespace std;
double donation[num];
double sum = 0;
double avg;
cout << "Enter a number(Stop when entering an unnumber):" << endl;
for (int i = 0; i < num; i++) {
cin >> donation[i];
/*if(!isdigit(donation[i])){
break;
}*/
sum += donation[i];
}
avg = sum / num;
cout << "The sum of all numbers is:" << avg << endl;
cout << "The number that is larger than avg is:" << endl;
for (int i = 0; i < num; i++) {
if (donation[i] > avg) {
cout << donation[i] << endl;
}
}
return 0;
}
3.编写一个菜单驱动程序的雏形。
该程序显示一个提供四个选项的菜单--每个选项用一个字母表标记。
如果用户使用有效选项之外的字母进行响应,程序将提示用户输入有效的字母,
直到用户这样选择为止。然后,该程序使用一条switch语句,根据用户的选择执行一个简单操作。该程序的运行情况如下:
Please enter one of the following choices:
c) carnivore p) pianist
t) tree g)game
f
Please enter a c,p,t or g:q
Please enter a c,p,t or g:t
A maple is a tree.
#include <iostream>
int main() {
using namespace std;
char ch;
cout << "Please enter one of the following choices:" << endl;
cout << "c) carnivore p) pianist" << endl;
cout << "t) tree g)game" << endl;
cin >> ch;
while (isalpha(ch)) {
switch (ch)
{
case 'c':
cout << "A maple is a carnivore." << endl;
break;
case 'p':
cout << "A maple is a pianist." << endl;
break;
case 't':
cout << "A maple is a tree." << endl;
break;
case 'g':
cou