Question

我正在尝试制作一个区域计算器，但我认为我通过定义长度和宽度搞砸了。我得到一个错误说错误：未初始化的const'length'[-fpermissive] | （宽度相同）我是编程新手

#include <iostream>
#include <string>
using namespace std;

int main()
{
const char length;
const char width;
cout << "Please enter the your length: ";
cin >> length;
cout << "Please enter your width: ";
cin >> width;
string area =
    length * width;
cout << " The area of these values is :" << area << "\n";
}

Answer 1

cin >> length;

您确定const char length;之类的变量声明吗？ const实际上表明，您无法更改这些变量值，并且尝试这样做是未定义的行为。

另请注意，length应该是size_t类型，而不仅仅是unsigned char，它最多只能容纳255个。

Answer 2

您的长度和宽度变量声明不应为const。您得到的错误是因为const值需要在声明时初始化（赋值给它们的值）。他们不能分配给他们的值，这是cin >>所做的。

Answer 3

代码有很多问题。

#include <iostream>
#include <string>
using namespace std;

int main()
{
    const char length;    // Making these const will break as soon as you try to write to it
    const char width;     //
    cout << "Please enter the your length: ";
    cin >> length;   // The fact you made it a char means it will only read the first char. "10" it would read "1"
    cout << "Please enter your width: ";
    cin >> width;
    string area =    // this will not work. There is no assignment operator for char to string 
        length * width;   
    cout << " The area of these values is :" << area << "\n";
}

固定

#include <iostream>
using namespace std;

int main()
{
    float length;
    float width;
    cout << "Please enter the your length: ";
    cin >> length;
    cout << "Please enter your width: ";
    cin >> width;
    float area = length * width;
    cout << " The area of these values is :" << area << "\n";
}

我很难理解我在制作这个计算器时做错了什么

3 个答案: