Thread: strcmp(), reading students' record and search for a particular name

Hi

I'm getting this error for the blue line in the code below: error: cannot convert 'bool' to 'const char*' for argument '1' to 'int strcmp(const char*, const char*)'.

How do I fix it? Please help me. Thanks.

Code:

// read students' record and search for data of a particular student.cpp
// use structure and display all data about the searched student

#include <iostream>
#include <cstdlib>
#include <cstring>

using namespace std;

const int C = 3;

struct Student {int rollno; char firstname[20]; char lastname[20]; string sex; float gpa;};

Student stud[C];

int main()
{
        int i; char searchname[30];

        for (i=0; i<C; i++)
        {
                cout << "\n\nEnter student #" << (i+1) << "\'s details below\n\n";
                cout << "enter roll no.: "; cin >> stud[i].rollno;
                cout << "enter first name: "; cin.get(stud[i].firstname, 20);
                cout << "enter last name: "; cin.get(stud[i].lastname, 20);
                cout << "enter sex: "; cin >> stud[i].sex;
                cout << "enter GPA: "; cin >> stud[i].gpa;
        }

        cout << "enter the name to be searched for: "; cin.get(searchname, 30);
        // name to be searched for could be, say, Jack Dawson

        for (i=0; i<C; i++)
        {
                if (strcmp( (stud[i].firstname && stud[i].lastname), searchname ) == 0)
                {
                        cout << "Data for the searched student is shown below\n";
                        cout << "roll no.: " << stud[i].rollno << endl;
                        cout << "first name: " << stud[i].firstname << endl;
                        cout << "last name: " << stud[i].lastname << endl;
                        cout << "sex: " << stud[i].sex << endl;
                        cout << "GPA: " << stud[i].gpa << endl;
                        break;
                 }

                 else
                 {
                         cout << "Sorry, no student exists with such name" << endl;
                         break;
                 }
        }

        system("pause");
        return 0;
}

> if (strcmp( (stud[i].firstname && stud[i].lastname), searchname ) == 0)
Compare each one separately
strcmp(a,b)==0 && strcmp(c,d)==0

Originally Posted by Salem

> if (strcmp( (stud[i].firstname && stud[i].lastname), searchname ) == 0)
Compare each one separately
strcmp(a,b)==0 && strcmp(c,d)==0

Thank you, Salem.

Can I do that? I have entered the student's first and last names separately but the name I want to search for is entered in one turn. Do you get what I'm trying to say? Please let me know if there is a way to fix it. Thanks.

I would join the 2 strings into one string before checking:

Code:

char Temp[ 300 ] = "" //Pretty big array
for (i=0; i<C; i++)
        {
                Temp[0] = '\0';
                strcat( Temp, stud[i].firstname );
                strcat( Temp, " " );
                strcat( Temp, stud[i].lastname );
                if (strcmp( Temp, searchname ) == 0)
                {
                        cout << "Data for the searched student is shown below\n";
                        cout << "roll no.: " << stud[i].rollno << endl;
                        cout << "first name: " << stud[i].firstname << endl;
                        cout << "last name: " << stud[i].lastname << endl;
                        cout << "sex: " << stud[i].sex << endl;
                        cout << "GPA: " << stud[i].gpa << endl;
                        break;
                 }

                 else
                 {
                         cout << "Sorry, no student exists with such name" << endl;
                         break;
                 }
        }

edit: sory about the mistake ^^'

I would not. That code is a ticking time bomb.

The note about a ticking time bomb is because you are using strcat without even bothering to check that you aren't overrunning your buffer. You see the additional complexity (and security issues!), which is why I would not use the approach.

That's just how scary that kind of code is. Bugs sneak in so easily and they are a huge security risk.
That's really why you shouldn't use such approaches--even for educational purposes--when there are much better alternatives.
This whole C-style C++ is what gave the language its bad name. It's such a shame, because it's such a wonderful--and safe--language.

Yes, it would get rid of the problem.