Question

我有这个包含以下错误的C ++代码：
1. readBinaryFile未在此范围内宣布 2. ret未在此范围内声明 3. recursiveBinarySearch未在此范围内声明。

有人可以帮我理解为什么会出现这些错误吗？

提前谢谢。

BinarySearch.h

    #ifndef BINARYSEARCH_H
    #define BINARYSEARCH_H

    using namespace std;

    class BinarySearch
    {

       public:
           char readBinaryFile(char *fileName);
           int recursiveBinarySearch(int start_index, int end_index, int        targetValue);
    };

    #endif

BinarySearch.cpp

    #include<iostream>
    #include<fstream>
    #include<cstdlib>
    #include<vector>
    using namespace std;

    //vector to dynamically store large number of values...
    vector<unsigned int> ret; 

    //variable to count the number of comparisions...  
    int n=0;  
    //method to read file....  
    void readBinaryFile(char* fileName)
    {
        ifstream read(fileName);
        unsigned int current;
        if(read!=NULL)
        while (read>>current) {
            ret.push_back(current);
        }

    }

    //recursive binary search method

    void recursiveBinarySearch(int start_index, int end_index, int targetValue)
    {

       int mid = (start_index+end_index)/2;

       if(start_index>end_index)
       {
          cout<<n<<":-"<<endl;
           return ;  
       }

       if(ret.at(mid)==targetValue)
       {
          n++;
           cout<<n<<":"<<mid<<endl;
           return ;  
       }
       else if(ret.at(mid)<targetValue)
       {
           n=n+2;//upto here two comparisions have been made..so adding two
           start_index=mid+1;
           return recursiveBinarySearch(start_index,end_index,targetValue) ;
       }
       else
       {
           n=n+2;
           end_index=mid-1;
           return recursiveBinarySearch(start_index,end_index,targetValue) ;
       }
    }

BinarySearch_test.cpp

    #include "BinarySearch.h"
    #include <iostream>
    #include <fstream>
    using namespace std;

    int main()
    {

       char a[] ="dataarray.bin";
       //assuming that all integers in file are already in sorted order
       readBinaryFile(a);

       int targetValue;
       cout<<"Enter a Value to search:";
       cin>>targetValue;

       recursiveBinarySearch(0,ret.size()-1,targetValue) ;


       return 0;

    }

Answer 1

在.cpp文件中，您错过了类名称来定义BinarySearch::

的函数

void BinarySearch::readBinaryFile(char* fileName)
{
   //code here
}

并且如上所述，由于这些方法不是静态的，因此您需要一个对象来调用它们。

BinarySearch x;
x.readBinary(...);

为什么我收到此错误：未在此范围内声明

1 个答案: