Question

我正在尝试编写一个小程序，它接受用户定义的有限字符串（小写字母，括号和+和*运算符）的字符串，查看每个字符，并将它们组织成单独的阵列。我认为我对这个练习的方法相当简单，但我遇到了一些我无法弄清楚的问题。

当我尝试将各个阵列打印到屏幕时，我的问题变得明显。如果所有字符都是相同类型（例如，＆＃34; abcd＆＃34;），则阵列按预期打印。但是如果存在字符类型的组合（例如，＆＃34;（a + b）＆＃34;），则阵列打印不正确。我很惭愧地说我现在已经在这个（可能是显而易见的）问题上敲了几个小时，而且似乎无法弄清楚我做错了什么。任何输入都会受到赞赏 - 我不是在寻找编写程序的帮助，我只是想知道我做错了什么。我在下面提供了我的代码：

#include <iostream>
#include <string>

using namespace std;

void charOrganizer(int[], char[], char[], char[], int, int&, int&, int&);

int main()
{
//Variable declaration
string userExpression;
int expressionArray[userExpression.length()];
char letterToken[userExpression.length()];
char parenthesesToken[userExpression.length()];
char plusTimesToken[userExpression.length()];
int letterTokenPos = 0;
int parenthesesTokenPos = 0;
int plusTimesTokenPos = 0;

//Prompt user for string input
cout << "Please enter a mathematical expression only using lowercase letters of the \nalphabet, parentheses, and/or the addition/multiplication operators."<< endl;
cin >> userExpression;

int arraySize = userExpression.length();

for (int i = 0; i < arraySize; ++i)
{
    expressionArray[i] = userExpression[i];
}

charOrganizer(expressionArray, letterToken, parenthesesToken, plusTimesToken, arraySize, letterTokenPos, parenthesesTokenPos, plusTimesTokenPos);

//Print tokens to screen
cout << "LowerCase Letter Token values in your string:" << endl;
for (int i = 0; i < letterTokenPos; i++)
{
    cout << letterToken[i] << endl;
}

cout << "Parentheses Token values in your string:" << endl;
for (int i = 0; i < parenthesesTokenPos; i++)
{
    cout << parenthesesToken[i] << endl;
}

cout << "Operator Token values in your string:" << endl;
for (int i = 0; i < plusTimesTokenPos; i++)
{
    cout << plusTimesToken[i] << endl;
}

return 0;
}

void charOrganizer (int charValue[], char letArr[], char parArr[], char pluTimArr[], int size, int& letPosition, int&parPosition, int& operPosition)
{   
for (int i = 0; i < size; i++)
{
    if (charValue[i] > 96 && charValue[i] < 123)
    {
        letArr[letPosition] = charValue[i];
        cout << "Letter Copy Test: " << letArr[letPosition] << endl;
        letPosition++;
    }

    else if (charValue[i] == 40 || charValue[i] == 41)
    {
        parArr[parPosition] = charValue[i];
        cout << "Parentheses Copy Test: " << parArr[parPosition] << endl;
        parPosition++;
    }

    else if (charValue[i] == 42 || charValue[i] == 43)
    {
        pluTimArr[operPosition] = charValue[i];
        cout << "Operator Copy Test: " << pluTimArr[operPosition] << endl;
        operPosition++;
    }

    else
    {
        cout << "Invalid input" << endl;
    }
}

/*cout << "Print Array Test: " << endl;
for (int i = 0; i < letPosition; i++)
{
    cout << letArr[i] << endl;
    //cout << parArr[i] << endl;
    //cout << pluTimArr[i] << endl;
}*/
}

Answer 1

请参阅以下代码。您正在使用空字符串的长度来声明数组大小，如下所示。在这种情况下，所有数组大小仅为零大小。正确纠正： -

//Variable declaration
string userExpression;
int expressionArray[userExpression.length()];// it would be just like int expressionArray[0];
char letterToken[userExpression.length()];
char parenthesesToken[userExpression.length()];
char plusTimesToken[userExpression.length()];

int expressionArray[30];
char letterToken[30];
char parenthesesToken[30];
char plusTimesToken[30];

另外，在输入字符串后声明这些变量。

在C ++中将数组的字符类型组织成单独的数组

1 个答案: