目前编写这个简单的代码,试图弄清楚为什么每次都没有计算特定的单词。
#include "pch.h"
#include <fstream>
#include <string>
#include <iostream>
using namespace std;
int main()
{
int t = 0;
int a1 = 0;
string a[100];
ifstream food;
food.open("food.txt");
if (food.fail())
{
cout << "File can't open" << endl;
}
else
cout << "File successfully opened" << endl;
int i = 0;
while (!food.eof())
{
// Tomato
food >> a[i];
if (a[i] == "tomato")
{
t = t + 1;
}
i++;
// Apple
food >> a[i];
if (a[i] == "apple")
{
a1 = a1 + 1;
}
i++;
}
cout << "Amount of Tomatos: " << t << endl;
cout << "Amount of Apples: " << a1 << endl;
}
我正在使用的文本文件:
apple
apple
tomato
apple
tomato
tomato
输出:
File successfully opened
Amount of Tomatoes: 2
Amount of Apples: 2
目的是找到列表中找到的每种食物的数量。我目前只使用两种食物,但会有更多食物。
您的代码有几个问题。
eof()
不正确。在首先执行读取操作之前,您无法检查eof()
。apple
。因为它不是"tomato"
,你跳过它并阅读文件中的下一个单词,即"apple"
,所以你算了。但你根本没有计算第一个apple
。你需要做更像这样的事情:
#include "pch.h"
#include <fstream>
#include <string>
#include <iostream>
using namespace std;
int main()
{
int tomatoes = 0;
int apples = 0;
string s;
ifstream food;
food.open("food.txt");
if (!food.is_open())
{
cout << "File can't open" << endl;
return 0;
}
cout << "File successfully opened" << endl;
while (food >> s)
{
// Tomato
if (s == "tomato")
++tomatoes;
// Apple
else if (s == "apple")
++apples;
}
cout << "Amount of Tomatos: " << tomatoes << endl;
cout << "Amount of Apples: " << apples << endl;
return 0;
}
或者,如评论中提到的@ user463035818,您可以使用std::map
代替:
#include "pch.h"
#include <fstream>
#include <string>
#include <iostream>
#include <map>
using namespace std;
int main()
{
map<string, int> foods;
string s;
ifstream food;
food.open("food.txt");
if (!food.is_open())
{
cout << "File can't open" << endl;
return 0;
}
cout << "File successfully opened" << endl;
while (food >> s) {
foods[s]++;
}
for (map<string, int>::iterator iter = foods.begin(); iter != foods.end(); ++iter) {
cout << "Amount of " << iter->first << ": " << iter->second << endl;
}
/* or, if you are using C++11 or later...
for (auto &item : foods) {
cout << "Amount of " << item.first << ": " << item.second << endl;
}
*/
return 0;
}