如何停止循环在C++中添加字符的额外迭代？

因此，我的代码如下：

if (x > y)
{
    cout << "Sum of the values from " << y << " through " << x << " is: " << endl;
    while (x >= y)
    {
        cout << y << " + ";
        sum += y;
        y++;
    } 
    cout << " = " << sum << endl;

}

执行此操作时，它的末尾有一个额外的加法符号，因此它将输出如下内容：

10+11+12+13+=46

---

我意识到循环在做什么，它为什么会在末尾添加加法符号对我来说是有意义的，但我不确定该将该语句放在哪里。任何帮助都将不胜感激

最简单的解决方案是明确地处理最终案例。即

 while (x > y)
{
    cout << y << " + ";
    sum += y;
    y++;
} 

cout << y;
sum += y;

cout << "Sum of the values from " << y << " through " << x << " is: " << endl;
while (x > y) //now the last case doesn't go through the loop
{
    cout << y << " + ";
    sum += y;
    y++;
}
cout << y << " = "; //instead it is handled here, and there will be no extra + sign
sum += y;
cout << sum << endl;

---

\b是一个退格转义序列，你可以用这个来擦除最后的+

if (x > y)
{
    cout << "Sum of the values from " << y << " through " << x << " is: " << endl;
    while (x >= y)
    {
        cout << y << " + ";
        sum += y;
        y++;
    } 
    cout << "\b\b= " << sum << endl;     // Change is here...

}

---

例如，您可以用以下方式编写

do
{
    cout << y;
    sum += y;
} while ( y++ < x && cout << " + " );

或

或

---

最简单的方法可能是平底船：

改变

cout << " = " << sum << endl;

---

在数字更简单之前添加加号：

if (x > y)
{
    int sum = y;
    cout << "Sum of the values from " << y << " through " << x << " is: " << endl << y;
    ++y;
    while (x >= y)
    {
        cout << " + " << y ;
        sum += y;
        y++;
    } 
    cout << " = " << sum << endl;
}

---

非常感谢。出于某种原因，我只是假设将它置于循环之外会导致它重复，但这是有道理的

cout << " = " << sum << endl;

cout << " 0 = " << sum << endl;

int a[] = {1,2};
int b[] = {1,2,};

if (x > y)
{
    int sum = y;
    cout << "Sum of the values from " << y << " through " << x << " is: " << endl << y;
    ++y;
    while (x >= y)
    {
        cout << " + " << y ;
        sum += y;
        y++;
    } 
    cout << " = " << sum << endl;
}