如何查找用戶使用do/while輸入的幾個整數的總和，while語句或For語句

Question

請幫忙在這裏。我想創建一個用戶輸入多個數字的程序（假設他/她的頭上有6個數字）。程序應該繼續計算所有這些數字的總和。然而，我必須使用循環語句，For語句，While語句或do/while語句。這是我到目前爲止有：

#include <iostream> 

using namespace std; 

int main() 
{ 
    int count = 1; 
    int sum = 0; 
    int number; 
    int numberitems; 

    cout << "Enter number of items: \n"; 
    cin >> numberitems; 

    cout << "Enter number: \n"; 
    cin >> number; 

    do { 

     sum = sum + number; 

     count++; 
    } while (count <= 6); 
} 

，這裏是另一個代碼中使用while語句

#include <iostream> 

using namespace std; 

int main() 
{ 
    int count = 1; 
    int sum = 0; 
    int number; 

    cout << "Enter number: \n"; 
    cin >> number; 

    while (count <= 6) { 
     sum = sum += number; 

     count++; 
    } 
    cout << sum << endl; 
} 

我知道這是初學者的東西，以及是初學者所以幫了妹妹禮貌。 感謝

Answer 1

for循環運作良好，我修改了它一點點：

#include<iostream> 
using namespace std; 
int main() 
{ 

    int sum = 0; 
    int number; 
    int numberitems; 


    cout << "Enter number of items: \n"; 
    cin >> numberitems; 

    for(int i=0;i<numberitems;i++) 
    { 
     cout << "Enter number: \n"; 
     cin >> number; 

     sum=sum+number; 

    } 
    cout<<"sum is: "<< sum<<endl; 
} 

無論其，WHILE循環在第11行出現了一些錯誤（Count未在此範圍內聲明）。可能是什麼問題？另外，如果你有一個使用DO的解決方案，那麼WHILE循環會很棒。謝謝

Answer 2

你應該這樣做：

#include<iostream> 
using namespace std; 
int main() 
{ 

    int sum = 0; 
    int number; 
    int numberitems; 


    cout << "Enter number of items: \n"; 
    cin >> numberitems; 

    for(int i=0;i<numberitems;i++) 
    { 
     cout << "Enter number <<i<<":" \n"; 
     cin >> number; sum+=number; 
    } 
    cout<<"sum is: "<< sum<<endl; 
} 

並配有while語句

#include <iostream> 
using namespace std; 
int main() 
{ 
    int sum = 0; 
    int number; 
    int numberitems; 
    cin>>numberitems; 

    cout << "Enter number: \n"; 

    while (count <=numberitems) 
    { 
     cin >> number; 
     sum+=number; 
    } 
    cout << sum << endl; 
} 

Answer 3

請注意，如果你要添加東西，你可能總是想檢查你是否超出int（特別是在作業練習中）的限制。 另外，int main()應返回int。

使用 「做..而」 循環：

#include<iostream> 
using namespace std; 
int main() 
{ 

    int sum = 0; 
    int previous = 0; 
    int number; 
    int numberitems; 
    int count = 0; 

    cout << "Enter number of items: "; 
    cin >> numberitems; 

    if (numberitems <= 0) 
    { 
    //no request to perform sum 
    cout << "Quitting without summing.\n\n"; 
    return 0; 
    } 

    do 
    { 
    cout << "Enter number to add : "; 
    cin >> number; 

    sum+=number; 

    // check here that the addition didn't break anything. 
    // Negative + negative should stay negative, positive + postive should stay positive 
    if ((number > 0 && previous > 0 && sum < 0) || (number < 0 && previous < 0 && sum > 0)) 
    { 
     cout << "Error: Beyond int limits !!"; 
     return 1; 
    } 

    count++; 
    previous = sum; 

    } 
    while (count < numberitems); 

    cout<<"sum is: "<< sum<<endl; 

    return 0; 
} 

Answer 4

#include<iostream> 
int main() 
{//initialize variables 
    int limit; 
    int num; 
    int sum=0; 
    int counter=0; 

    cout<<"Enter limit of numbers you wish to see"<<" "; 
    cin>>limit; 
    cout<<endl; 

while(counter<limit) 
{ 

    cout<<"Enter number "<<endl; 
    cin>>num; 

    sum=sum+num; 
    counter++; 
} 
cout<<"The sum of numbers is "<<" "<<endl 

return 0; 
} 

Answer 5

一個簡單的程序展示瞭如何使用for循環找到serveral的整數的總和。

#include <iostream>  
using namespace std; 

int main() 
{ 
    int sum = 0; 

    int endnum = 2; 

    for(int i = 0; i<=endnum; i++){ 
     sum += i; 
    } 
    cout<<sum; 
}