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POSegmentation fault in class definitions cannot figure out where
 

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  1. POSegmentation fault in class definitions cannot figure out where
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    <p>I am having a segmentation error that I have been trying to find for the past 4 hours. Here is the code and some information that might be of use from valgrind.</p> <pre><code> Course::Course() { courseid = "None"; courseName = "None"; enrolled[2] = {0}; } Course::Course(string courseNum, string coursename, string filename) { courseid = courseNum; courseName = coursename; enrolled[2] = {0}; readStudentData(filename); sortRow(0); sortRow(1); sortRow(2); } void Course::readStudentData(string filename) { std::ifstream inFile; //declare file input stream object string first, last, zid; int section; inFile.open(filename.c_str()); //open file if (!inFile) { cout &lt;&lt; "File did not open successfully!"; //error checking exit(EXIT_FAILURE); } inFile &gt;&gt; first; //read first while (inFile) { inFile &gt;&gt; last; inFile &gt;&gt; zid; inFile &gt;&gt; section; section--; //match section with array subscript Student newStudent(last, first, zid); //fill contents read to new student object Students[section][enrolled[section]] = newStudent; //fill Students array with new student enrolled[section]++; //add the student to the enrolled counter inFile &gt;&gt; first; } inFile.close(); } void Course::sortRow(int RowtoSort) { int i, j; Student bucket; for(i = 1; i &lt; enrolled[RowtoSort];i++) { bucket = Students[RowtoSort][i]; //assign bucket with temp value for swap for(j = i; (j &gt; 0) &amp;&amp; (Students[RowtoSort][j-1].getLastName().compare(bucket.getLastName())) &lt; 0; j--) { Students[RowtoSort][j] = Students[RowtoSort][j-1]; //assign j to element j-1 so now both j and j-1 are the same in the array } Students[RowtoSort][j] = bucket; //now j-1 value is at j and since j-- assign it to bucket to place the proper value at j-1 } // end outer loop } void Course::print() { cout &lt;&lt; courseid &lt;&lt; " " &lt;&lt; courseName &lt;&lt; endl; //header cout &lt;&lt; "Section 1" &lt;&lt; endl; //print section 1 cout &lt;&lt; left &lt;&lt; "Name" &lt;&lt; setw(40) &lt;&lt; "Z-id" &lt;&lt; endl; for(int i=0;i&lt;enrolled[0];i++) { Students[0][i].print(); } cout &lt;&lt; "Section 2" &lt;&lt; endl; //print section 2 cout &lt;&lt; left &lt;&lt; "Name" &lt;&lt; setw(40) &lt;&lt; "Z-id" &lt;&lt; endl; for(int i=0;i&lt;enrolled[0];i++) { Students[1][i].print(); } cout &lt;&lt; "Section 3" &lt;&lt; endl; //print section 3 cout &lt;&lt; left &lt;&lt; "Name" &lt;&lt; setw(40) &lt;&lt; "Z-id" &lt;&lt; endl; for(int i=0;i&lt;enrolled[0];i++) { Students[2][i].print(); } } </code></pre> <p>Here is the information valgrind gave when</p> <pre><code>==4223== Use of uninitialised value of size 8 ==4223== at 0x4EF15F1: std::string::assign(std::string const&amp;) (in /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.17) ==4223== by 0x4023E6: Student::operator=(Student const&amp;) (in /home/ruslan/241Assign3/assign3) ==4223== by 0x401B9F: Course::readStudentData(std::string) (in /home/ruslan/241Assign3/assign3) ==4223== by 0x401836: Course::Course(std::string, std::string, std::string) (in /home/ruslan/241Assign3/assign3) ==4223== by 0x4012F9: main (assign3.cpp:27) ==4223== ==4223== Use of uninitialised value of size 8 ==4223== at 0x4EF15F1: std::string::assign(std::string const&amp;) (in /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.17) ==4223== by 0x402401: Student::operator=(Student const&amp;) (in /home/ruslan/241Assign3/assign3) ==4223== by 0x401B9F: Course::readStudentData(std::string) (in /home/ruslan/241Assign3/assign3) ==4223== by 0x401836: Course::Course(std::string, std::string, std::string) (in /home/ruslan/241Assign3/assign3) ==4223== by 0x4012F9: main (assign3.cpp:27) ==4223== ==4223== Use of uninitialised value of size 8 ==4223== at 0x4EF15F1: std::string::assign(std::string const&amp;) (in /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.17) ==4223== by 0x40241C: Student::operator=(Student const&amp;) (in /home/ruslan/241Assign3/assign3) ==4223== by 0x401B9F: Course::readStudentData(std::string) (in /home/ruslan/241Assign3/assign3) ==4223== by 0x401836: Course::Course(std::string, std::string, std::string) (in /home/ruslan/241Assign3/assign3) ==4223== by 0x4012F9: main (assign3.cpp:27) ==4223== ==4223== Invalid read of size 8 ==4223== at 0x4EF15F1: std::string::assign(std::string const&amp;) (in /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.17) ==4223== by 0x4023E6: Student::operator=(Student const&amp;) (in /home/ruslan/241Assign3/assign3) ==4223== by 0x401B9F: Course::readStudentData(std::string) (in /home/ruslan/241Assign3/assign3) ==4223== by 0x401836: Course::Course(std::string, std::string, std::string) (in /home/ruslan/241Assign3/assign3) ==4223== by 0x4012F9: main (assign3.cpp:27) ==4223== Address 0x8050190f0 is not stack'd, malloc'd or (recently) free'd ==4223== ==4223== ==4223== Process terminating with default action of signal 11 (SIGSEGV) ==4223== Access not within mapped region at address 0x8050190F0 ==4223== at 0x4EF15F1: std::string::assign(std::string const&amp;) (in /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.17) ==4223== by 0x4023E6: Student::operator=(Student const&amp;) (in /home/ruslan/241Assign3/assign3) ==4223== by 0x401B9F: Course::readStudentData(std::string) (in /home/ruslan/241Assign3/assign3) ==4223== by 0x401836: Course::Course(std::string, std::string, std::string) (in /home/ruslan/241Assign3/assign3) ==4223== by 0x4012F9: main (assign3.cpp:27) </code></pre> <p>I have another student class which has been complied and been tested to work correctly so the error must be in the course.</p> <p>Course Header file:</p> <pre><code>#ifndef COURSE_H #define COURSE_H #include "student.h" using std::string; class Course { private: string courseid; string courseName; Student Students[3][45]; int enrolled[2]; public: Course(); //default constructor Course(string, string, string); //alternate constructor void readStudentData(string); void sortRow(int); void print(); }; #endif //COURSE.H </code></pre> <p>Student class definitions:</p> <pre><code>Student::Student() { firstName = "None"; lastName = "None"; zid = "None"; } Student::Student(string assignFirst, string assignLast, string assignZID) { firstName = assignFirst; lastName = assignLast; zid = assignZID; } string Student::getLastName() { return lastName; } void Student::print() { cout &lt;&lt; lastName &lt;&lt; ", " &lt;&lt; firstName &lt;&lt; std::setw(15) &lt;&lt; zid &lt;&lt; endl; } </code></pre>
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    1. PO
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    1. This table or related slice is empty.
    1. PTQuestion
    1. USScholar
    1. USScholar
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    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
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      1. PTAnswer
    1. This table or related slice is empty.
    1. COhow array Students is defined?
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      1. POSegmentation fault in class definitions cannot figure out where
      1. USIłya Bursov
    2. CORun your program in a debugger. It will stop when the crash happens, and allows you to see (and walk) the call stack. If the crash is not in your code, then walk up the call stack until you reach your code, then you can examine values of variables. Or look at the message Valgrind gave you, it tells you that the crash happened at `Student::operator=(Student const&)`, so you can start by posting that function.
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      1. POSegmentation fault in class definitions cannot figure out where
      1. USSome programmer dude
    3. COcould show us the class `Course` declaration (header file)
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      1. POSegmentation fault in class definitions cannot figure out where
      1. USlolando
 

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