Hello I'm writing a small program that allows the user to enter three test scores for a number of students than to compute student average, give a letter grade than give class average for each test once the user has given no (n) as an answer. For some reason I'm getting a very large number for total test 3 (tottest3) I've been looking at the code for almost an hour and a half now and I can't find the error.
the formulas for total test 1 to three are all identical, would the problem lie else where?
here is what I've tried doing so far:
-changing the average variable
-changing the class average to merely the total average
-adding test 1 or test 2 numbers to total test 3 instead of test 3 .
here is the output on command prompt.
Assignment #13
Hello Student #1
Please input test 1 Grade 1
Please input test 2 Grade 1
Please input test 3 Grade 1
Your Average is: 1
Your grade is F
Do you want to grade another student? (y/n) n
here are the averages for tests 1-3
average for test 1 is: 1
average for test 2 is: 1
average for test 3 is: 335796348684545909624128047159363492209569460693822234007169656776676343892387006827439949582508669307827616982407178504474449980239883634115896048874405460441709614779949982258368367180374307657350038129751972987645105499446376379659139781953069252608
Process exited with return value 0
Press any key to continue . . .
#include<iostream>
#include<cmath>
#include<iomanip>
using namespace std;
int main ()
{
cout<<"Jon Grezda CS 12 Wednesday 6-8pm"<<endl;
cout<<"Assignment #13"<<endl;
double test1, test2, test3, average; //test1/2/3, test scores, Average: average of test scores
double tottest1, tottest2, tottest3, avg1, avg2, avg3; //tottest1/2/3, avg# average for first second or third test
int student=0, avgvar; //average variable, Student number
char grade, ans; // Holds a letter grade, holds a response to a question
do{
student=student+1;
cout<<"Hello Student #"<<student<<endl;
cout<<"Please input test 1 Grade ";
cin>> test1;
cout<<"Please input test 2 Grade ";
cin>> test2;
cout<<"Please input test 3 Grade ";
cin>> test3;
average=(test1+test2+test3)/3.0;
cout<<setprecision(0)<<fixed;
cout<<"Your Average is: "<<average<<endl;
tottest1=tottest1+test1;
tottest2=tottest2+test2;
tottest3=tottest3+test3;
// Determine the letter grade. What grade will be assigned?
if (average > 0 && average < 60)
grade = 'F';
else if (average >= 61 && average < 70)
grade = 'D';
else if (average >= 70 && average < 80)
grade = 'C';
else if (average >= 80 && average < 90)
grade = 'B';
else if(average >= 90 && average <101)
grade = 'A';
else
{
cout << "We do not give scores higher than 100 or lower than 0.\n"; // Is the score valid?
grade = '-';
}
cout << "Your grade is " << grade << endl;
cout<<"Do you want to grade another student? (y/n)";
cin>>ans;
cout<<"\n";
} while(ans=='y');
if (ans=='n')
{
avgvar=student;
avg1=tottest1/avgvar;
avg2=tottest2/avgvar;
avg3=tottest3/avgvar;
cout<<setprecision(0)<<fixed;
cout<<"here are the averages for tests 1-3\n";
cout<<"average for test 1 is: "<<avg1<<endl;
cout<<"average for test 2 is: "<<avg2<<endl;
cout<<"average for test 3 is: "<<avg3<<endl;
}
}
/*
*/
Your trouble happens in these lines;
tottest1=tottest1+test1;
tottest2=tottest2+test2;
tottest3=tottest3+test3;
You declared the variables tottest1, tottest2, and tottest3 but you did not give them a value. Your program has set aside some memory for those variables but it has not placed a value into those spots of memory so they are just filled with garbage. When you try to assign values to the variables by adding test1/2/3 to them, you add something meaningful to whatever garbage was stored in those uninitialized slots of memory. The result is something meaningless.
Solution: When you declare a variable, make sure to initialize it with some value, eg, 0.
It doesn't look like you're initializing your variables. Do that and you'll get more predictable results. Probably set them to 0 initially.
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