Question

用户输入一个double和string，它存储在两个数组中。像这样：

{
                 double DoC;
                 string Nm;
                 cout << " Please enter the amount charged to your credit card " << endl;
                 cin >> DoC;
                 cout << " Please enter where the charge was made " << endl;
                 cin >> Nm;
                 getline(cin, Nm);
                 cca.doCharge(Nm,DoC);
                 break;
                 }

然后将double和string传递给：

{
    if (amount > 0)
    {
        for (int i = 9; i != 0; i--)
        { 
            last10withdraws[i] = last10withdraws[i-1];
            last10charges[i] = last10charges[i-1];
        }

        last10withdraws[0] = amount;
        last10charges[0] = name;

        setBalanceW(amount);  
    }
    else
    {
        cout << " ERROR. Number must be greater then zero. " << endl;
    }
    return 0;
}

这似乎非常适合将数据存储到数组中。但是，然后我使用此函数显示数组内部的数据：

{
    cout << " Account: Creditcard Withdraws " << " " << " Account: Creditcard Deposits " << " " << " Account: Creditcard last 10 charges " << endl;
    cout << "            " << last10withdraws[0] << "                       " << last10deposits[0] << "                       " << last10charges[0] << endl;
    cout << "            " << last10withdraws[1] << "                       " << last10deposits[1] << "                       " << last10charges[1] << endl;
    cout << "            " << last10withdraws[2] << "                       " << last10deposits[2] << "                       " << last10charges[2] << endl;
    cout << "            " << last10withdraws[3] << "                       " << last10deposits[3] << "                       " << last10charges[3] << endl;
    cout << "            " << last10withdraws[4] << "                       " << last10deposits[4] << "                       " << last10charges[4] << endl;
    cout << "            " << last10withdraws[5] << "                       " << last10deposits[5] << "                       " << last10charges[5] << endl;
    cout << "            " << last10withdraws[6] << "                       " << last10deposits[6] << "                       " << last10charges[6] << endl;
    cout << "            " << last10withdraws[7] << "                       " << last10deposits[7] << "                       " << last10charges[7] << endl;
    cout << "            " << last10withdraws[8] << "                       " << last10deposits[8] << "                       " << last10charges[8] << endl;
    cout << "            " << last10withdraws[9] << "                       " << last10deposits[9] << "                       " << last10charges[9] << endl;
    cout << endl;

}

让我们说用户已经在存款阵列中输入了三个双打。当我调用函数显示它时，我得到这样的东西：

60
30
20
-9.25596e+061
-9.25596e+061
-9.25596e+061
-9.25596e+061
-9.25596e+061
-9.25596e+061

如何才能使-9.25596e + 061为0？我找不到真正帮助我的任何东西。对于包含字符串的数组，当它被调用以显示它时，它什么都不显示。这是为什么？

Answer 1

将数组初始化为：

int last10withdraws[10] = {0};

现在所有元素都为零。

如果用户输入三个数字，则前三个元素将为非零（假设仅允许非零），其余元素将为零。

如果last10withdraws是m类的成员（并且您正在使用C ++ 03），则可以使用member-initializer list进行default-initialize，这会将所有元素初始化为零。 / p>

class myclass
{
      int last10withdraws[10];
   public:
      myclass() : last10withdraws() 
      {       //^^^^^^^^^^^^^^^^^^^ member initializer list
      }
};

希望有所帮助。

Answer 2

您收到错误是因为您没有初始化值。首先说int last10withdraws[10] = {0};这会将所有值初始化为零。

如果该插槽中没有输入，如何使数组打印零

2 个答案: