初學者C++ - 做一些簡單的計算

Question

所以我想做一些簡單的數學計算，但我甚至不能把一個數字放在一個變量中。

int choice; 
cout << "\nEnter your choice..." << endl; 
cin >> choice; 

if (choice == 1) { 
    cout << "All entries:" << endl; 

    sqlite::sqlite db("student_marks.sqlite"); 
    auto cur = db.get_statement();   
    cur->set_sql("SELECT * FROM marks;"); 
    cur->prepare(); 

    while(cur->step()) { 
     int apples = cur->get_text(2); 
     int cherries = cur->get_text(3); 
     int sumFruits = apples + cherries 
    } 
} 

給我的錯誤

error: no viable conversion from 'std::string' (aka 'basic_string<char, char_traits<char>, allocator<char> >') to 'int' 

我怎樣才能解決這個問題？如果我做

cout << "Bananas number : " << cur->get_text(3) << endl; 

它打印沒有任何問題的價值..

感謝

Answer 1

你需要一個std::string轉換爲int - 嘗試使用stoi()：

int apples = std::stoi(cur->get_text(2)); 
int cherries = std::stoi(cur->get_text(3));