我删除了有关开关语句代码的旧帖子/问题，因为我有一些明显的错别字，并创建了一个新文件。我的问题是，我仍然对该操作仍如何使用加法或等于声明的0感到困惑。我确实尝试使用（x = 0; x <2; x--）运行它，但最终结果为0。
这里是代码：
#include<iostream>
using namespace std;
int main(){
int x, num[2], ans = 0;
char operation;
int y,z;
cout<<"\n===== Operation =====";
cout<<"\n A - Addition";
cout<<"\n B - Subtraction";
cout<<"\n C - Multiplication";
cout<<"\n D - Division";
cout<<"\n E - Exit";
cout<<"\n\n Select operation (A,B,C,D or E to Exit): "; cin >> operation;
switch(operation){
case 'a':
case 'A':
cout << "\n You selected ADDITION";
cout << "\n Input 2 numbers: ";
for ( x = 0 ; x < 2 ; x++ )
{
cin >> num[2];
ans += num[2];
}
cout << "\n The answer is: " << ans << endl;
break;
case 'b':
case 'B':
cout << "\n You selected SUBTRACTION";
cout << "\n Input 2 numbers: ";
for ( x = 0 ; x < 2 ; x++ )
{
cin >> num[2];
ans -= num[2];
}
cout << "\n The answer is: " << ans << endl;
break;
default:
cout << "were you trying something else??? \n unless you are looking for this error. Congratulations!";
}
return 0;
}
您想做什么
for ( x = 0 ; x < 2 ; x++ ) {
cin >> num[x];
}
ans = num[0] + num[1];
代替
for ( x = 0 ; x < 2 ; x++ ) {
cin >> num[2];
ans += num[2];
}
以及类似的减法方法。
还请注意数组索引num[2]，第三个数组元素不适合两个元素int num[2];的数组。