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POfstream infinite loop while reading file in c++
 

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    <p>I'm in a CS101 class at my school using C++. I have a program that has to read a file in this format:</p> <pre><code>Ramirez, Manny 1572838992 a 4 b 5 x 4 a 7 c 3 c 4 * Kemp, Matt 3337474858 a 4 b 4 b 4 a 4 * </code></pre> <p>It is supposed to read the file, calculate the GPA of each student and output the student's name, ID, units, and GPA. I have been trying different things for a while now, and I've been going back and forth with infinite loops. I got help from a friend, who had me include some stuff. </p> <p>I have tried changing the condition of the loop inside the while (!eof) loop so many times I can't count them all. Every time I look up what to do online, the advice I get is just to not use while !eof because it has a propensity to cause infinite loops. Well, I know that now, but my professor wants us to do it that way. </p> <p>Here is my code:</p> <pre><code> #include &lt;iostream&gt; #include &lt;fstream&gt; #include &lt;string&gt; #include &lt;iomanip&gt; #include &lt;sstream&gt; using namespace std; int main() { char grade; int units=0, studentsGrade=0, studentUnits=0; int unitTotal=0; float gradeTotal=0, gpa = 0; string inputName, outputName, fullName; long ID; ifstream inputFile; ofstream outputFile; cout &lt;&lt; "Please enter the input filename: "; cin &gt;&gt; inputName; cout &lt;&lt; "Please enter the output filename: "; cin &gt;&gt; outputName; inputFile.open(inputName.c_str()); if (inputFile.fail()) cout &lt;&lt; "Bad input file name." &lt;&lt; endl; else { outputFile.open(outputName.c_str()); outputFile &lt;&lt; left &lt;&lt; setw(25) &lt;&lt; "Name" &lt;&lt; setw(15) &lt;&lt; "ID" &lt;&lt; setw(15) &lt;&lt; "Units" &lt;&lt; setw(15) &lt;&lt; "GPA" &lt;&lt; endl; outputFile &lt;&lt; "--------------------------------------------------------------------------------" &lt;&lt; endl; cout &lt;&lt; left &lt;&lt; setw(25) &lt;&lt; "Name" &lt;&lt; setw(15) &lt;&lt; "ID" &lt;&lt; setw(15) &lt;&lt; "Units" &lt;&lt; setw(15) &lt;&lt; "GPA" &lt;&lt; endl; cout &lt;&lt; "--------------------------------------------------------------------------------" &lt;&lt; endl; getline(inputFile, fullName); while (!inputFile.eof()) { gpa = 0; unitTotal = 0; gradeTotal = 0; inputFile &gt;&gt; ID; outputFile &lt;&lt; setw(25) &lt;&lt; fullName; outputFile &lt;&lt; setw(15) &lt;&lt; ID; cout &lt;&lt; setw(25) &lt;&lt; fullName &lt;&lt; setw(15) &lt;&lt; ID; string line; getline(inputFile,line); istringstream iss(line); while (!iss.eof()) { units = 0; iss &gt;&gt; grade &gt;&gt; units; if (grade == '*') break; if (units &gt; 0 &amp;&amp; units &lt;=5 &amp;&amp; (grade == 'a' || grade == 'A')) { gradeTotal += 4 * units; studentsGrade += 4 * units; unitTotal += units; studentUnits += units;} else if (units &gt; 0 &amp;&amp; units &lt;=5 &amp;&amp; (grade == 'b' || grade == 'B')) { gradeTotal += 3 * units; studentsGrade += 3 * units; unitTotal += units; studentUnits += units; } else if (units &gt; 0 &amp;&amp; units &lt;=5 &amp;&amp; (grade == 'c' || grade == 'C')) { gradeTotal += 2 * units; studentsGrade += 2 * units; unitTotal += units; studentUnits += units; } else if (units &gt; 0 &amp;&amp; units &lt;=5 &amp;&amp; (grade == 'd' || grade == 'D')) { gradeTotal += 1 * units; studentsGrade += 1 * units; unitTotal += units; studentUnits += units; } else if (units &gt; 0 &amp;&amp; units &lt;=5 &amp;&amp; (grade == 'f' || grade == 'F')) { unitTotal += units; studentUnits += units; } else if (grade == '*') { unitTotal += 0;} else { unitTotal += 0; } } gpa = (float)gradeTotal / unitTotal; outputFile &lt;&lt; fixed &lt;&lt; showpoint; outputFile &lt;&lt; setw(15) &lt;&lt; unitTotal &lt;&lt; setw(15) &lt;&lt; setprecision(2) &lt;&lt; gpa &lt;&lt; endl; cout &lt;&lt; fixed &lt;&lt; showpoint; cout &lt;&lt; setw(15) &lt;&lt; unitTotal &lt;&lt; setw(15) &lt;&lt; setprecision(2) &lt;&lt; gpa &lt;&lt; endl; getline(inputFile,fullName); } outputFile &lt;&lt; "The GPA for all students is " &lt;&lt; setprecision(2) &lt;&lt; (float)studentsGrade / studentUnits; cout &lt;&lt; "The GPA for all students is " &lt;&lt; setprecision(2) &lt;&lt; (float)studentsGrade / studentUnits &lt;&lt; endl; } inputFile.close(); outputFile.close(); cout &lt;&lt; endl; return 0; } </code></pre> <p>If anyone can explain to me why I keep getting an infinite loop, I would really appreciate it.</p>
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