Question

当我尝试使用＆＃34; isdigit＆＃34;在向量中找到任何非数字时，它似乎总是认为有非数字，即使没有任何数字。

这是我的代码：

vector<double> nums;      // vector to hold numbers from the file.

bool Numbers::Read (istream& istr)  // read in the numbers from the file
{


ifstream inputFile("nums.txt");   // open the file for reading

if (inputFile)
{

float meanTotal = 0.0; // mean value
double result;  // result of the numbers being added together
double count;   // count the amount of items in the file

while (inputFile >> count)  // read the numbers into the vector
{

    nums.push_back(count);
    ++count;



}

float numsSize = nums.size();   // size of the vector


for(int i = 0; i < numsSize; i++)
{



    if(isdigit(nums.at(i)))
    {

    }
    else
    {
        cout << "File contains non-integers" << endl;
        return -1;
    }

}



/* ADD ALL OF THE NUMBERS TOGETHER */

for(int i = 0; i < numsSize; i++)   // store the summation of the vector
{
    result += nums[i];
}


/* FIND THE MEAN OF THE NUMBERS ADDED */

meanTotal = result/numsSize;

float mean = meanTotal;


float dev = 0.0;
float devResult = 0.0;
float devHold = 0.0;


for(int i = 0; i < numsSize; i++)
{
    dev += (nums[i] - mean) * (nums[i] - mean);
}

devHold = dev / numsSize;

devResult = sqrt(devHold);

if (numsSize == 0)
{
    cout << "UNDEFINED" << " " << "UNDEFINED" << endl;
}
else if (numsSize == 1)
{
    cout << mean << " " << "UNDEFINED" << endl;
}
else
    cout << mean << " " << devResult << endl;
}

return true;

}

我想确保文本文件中只有空格和数字。＆＃34; ISDIGIT＆＃34;似乎并不像我想要的那样工作。我假设即使向量通过跳过不是数字的所有内容来读取文件，也不会以相同的方式运行。

我现在意识到＆＃34; isdigit＆＃34;没有双打工作。那么如何检查输入文件中的非数字呢？

Answer 1

函数isDigit和其他类似的函数都使用char类型。因此，你在doulbe（conunt）上使用它，你会得到错误的结果。

在向量中查找非数字

1 个答案: