我试图抛出一个学生对象的向量。如果我找到与我正在搜索的ID相匹配的ID,则会显示其信息。
然而,当我尝试找到一个特定的ID时,.compare没有看到匹配,即使它应该。
我的输出:第一行是我要查找的ID,第二行是当前查看的ID,然后是比较的结果。
a11111111
a22222222
-1
no match
a11111111
a11111111
-1
no match
要求更多代码,所以这里是整个程序:(在displayID中的问题)
头文件
#ifndef structures_h
#define structures_h
#include <vector>
#include <iostream>
#include <stdlib.h>
#include <stdio.h>
#include <fstream>
#include <sstream>
#include <string>
#include <algorithm>
#include <stdio.h>
#include <map>
using namespace std;
主程序
#endif
typedef pair<string, string> Name; // first name, last name
typedef map<string, int> Grades; // map courses to scores
#include "struct.h"
class Student {
public:
void display(ostream& os) const;
void setId(string);
void setName(string, string);
void setGrades(string, int);
string getId();
string getName();
void getGrades();
bool operator<(const Student &rhs) const { return id_ < rhs.id_; }
private:
string id_; // e.g. "a22222222"
Name name_; // e.g. {"ned", "flanders"}
Grades grades_;
};
void Student::setId(string id) {
id_ = id;
}
string Student::getId() {
return id_;
}
void Student::setName(string first, string last) {
name_ = pair<string,string>(first, last);
}
string Student::getName() {
return get<0>(name_) + ' ' + get<1>(name_);
}
void Student::setGrades(string course, int score) {
grades_.insert(make_pair(course, score));
}
void Student::getGrades() {
for(auto it = grades_.begin(); it != grades_.end(); ++it) {
cout << it -> first << ' ' << it -> second << endl;
}
}
vector<Student> addStudent(int count, int x, vector<Student>& vStu, string file) {
string line, first, last;
ifstream infile(file);
while (getline(infile, line)) {
vStu.push_back(Student());
vStu[count].setId(line);
getline(infile, line);
istringstream iss(line);
if (!(iss >> first >> last)) {
cout << "failed to get name" << endl;
break;
}
vStu[count].setName(first, last);
getline(infile, line);
istringstream iss2(line);
if (!(iss2 >> x)) {
cout << "failed to get class number" << endl;
break;
}
for (int i = 0; i < x; i++) {
string sClass;
int grade;
getline(infile, line);
istringstream iss3(line);
if (!(iss3 >> sClass >> grade)) {
cout << "failed to get class and grade" << endl;
break;
}
vStu[count].setGrades(sClass, grade);
}
count++;
}
return vStu;
}
void display(vector<Student>& vStu) {
sort(vStu.begin(), vStu.end());
cout << endl;
int count = vStu.size();
for (int i = 0; i<count;i++) {
cout << vStu[i].getId() << endl;
cout << vStu[i].getName() << endl;
vStu[i].getGrades();
cout << endl;
}
}
void displayID(vector<Student>& vStu, string ID) {
int count = vStu.size();
string test;
ID = "a11111111";
for (int i = 0; i<count;i++) {
cout<< endl;
test = vStu[i].getId();
cout << ID << endl;
cout << test << endl;
cout << ID.compare(test) << endl;
if (ID.compare(test) == 0) {
cout << "match" << endl;
cout << vStu[i].getId() << endl;
cout << vStu[i].getName() << endl;
vStu[i].getGrades();
cout << endl;
} else {
cout << "no match" << endl;
}
}
cout << endl;
}
void mainMenu(vector<Student>& vStu) {
string input;
string word;
vector<string> com;
while(1) {
cout << "Enter command: ";
getline(cin,input);
istringstream iss(input);
while(iss >> word) {
com.push_back(word);
}
for (int i = 0; i < (int)com.size(); i++) {
transform(com[i].begin(), com[i].end(), com[i].begin(), ::tolower);
if (com[i] == "show") {
display(vStu);
} else if (com[i] == "showid") {
displayID(vStu, "a11111111");
}
}
com.clear();
}
}
int main(int argc, char *argv[]) {
vector<Student> vStu;
int count = 0, x = 0;
if (argc != 2) {
cout << "Incorrectly called" << endl;
cout << " " << argv[0] << ' ' << "<filename>" << endl;
return 1;
}
addStudent(count, x, vStu, argv[1]);
mainMenu(vStu);
}
答案 0 :(得分:0)
我看到的唯一可能性是string
末尾有一些空格被传递到你的函数中。在比较之前尝试修剪string
的结尾,如this thread所示,并查看它们是否仍然无法正确比较。