c++ string checking

chess (19)
Hi
here is my program, my question is about firtname and lastname part, the question wants to check for input error , namely if user enters anything other than upper and lower case letters and hyphens for the firstname and lastname , program complains and dies immidiately. how can I do that in my program.(cin mustbe used as well.)
Thanks.


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#include <iostream>
#include <string>
#include<cstdlib>
using namespace std;

 struct Student {
		string firstName;
		string lastName;
		unsigned number;
		unsigned units;
		unsigned gradePoints;
};
 void input(Student &x);
 void output(Student &x);
 void takeClass(Student &x, unsigned N_units, char grade);
 double gpa(Student &x);
 int main()
 {
	 /*unsigned N_units;
	 char grade;*/
  Student NewStudent;
  input(NewStudent);
  /*output(NewStudent);
  takeClass(NewStudent,3,'A');
  output(NewStudent); 
  cout<<" GPA is equal to"<<gpa(NewStudent)<<endl;*/
	 return 0;
 }
	
 void input(Student &x)
 {
	 char Answer='y',grade;
	 
	  cout<<"Enter your First Name:\n";           /*This part is my problem , how to check
	  cin>>x.firstName;                                         for input errors.
	  cout<<"Enter your last Name:\n";               */
	  cin>>x.lastName;
	 

	  cout<<"Enter you Student Number:\n";
	  cin>>x.number;
	  if(x.number<100000000 || x.number>999999999)
		{
			cout<<"invalid student number\n";
			exit(EXIT_FAILURE);
		} 
		cout<<"How many units you have taken:\n";
	  cin>>x.units;
	  if(x.units>1000000 || x.units<0)
		{
		 cout<<"Invalid number of units:\n";
		 exit(EXIT_FAILURE);
	    }

      cout<<"Enter your number of gradePoints:\n";
	  cin>>x.gradePoints;
	 if(x.gradePoints> 4 * x.units)
	   {
		   cout<<"Invalid total number of gradepoints:\n ";
		   exit(EXIT_FAILURE);
	   }	

	 while(Answer=='y')
	 {
        
	  cout<<"How many units you have taken:\t";
	  cin>>x.units;
	  if(x.units>1000000 || x.units<0)
		{
		 cout<<"Invalid number of units:\n";
		 exit(EXIT_FAILURE);
	    }
	  
      cin>>grade;
	  if((grade!='A' && grade!='B' && grade!='C' && grade!='D' && grade!='E'))
	    {
		  cout<<"Invalid grade letter\n";
          exit(EXIT_FAILURE);
	    }
	 cout<<"Would you like to continue and Enter your number of units and your grade letter?(y/n)\n";
	  cin>>Answer;
	 }

 }
	 

 void output(Student &x)
 {
	 cout<<"Your name is:  "<<x.firstName<<" "<<x.lastName<<"  ";
	 cout<<"Your student number is "<<"#"<<x.number<<"  ";
	 cout<<"You have taken "<<x.units<<" units"<<"  ";
	 cout<<"Your total grade points are "<<x.gradePoints<<"  ";
	 cout<<"Your GPA is"<<(x.gradePoints)/x.units<<endl<<"  ";
 }

  void takeClass(Student &x, unsigned N_units, char grade)
  {
	  int k;
	  if(N_units>24 || (grade!='A' && grade!='B' && grade!='C' && grade!='D' && grade!='E'))
	  {
		  cout<<"Your data cannot be updated"<<endl;
		  exit(EXIT_FAILURE);
	  }
	  if(grade=='A')
		  k=4;
	  else if(grade=='B')
		  k=3;
	  else if (grade=='C')
		  k=2;
	  else if(grade=='D')
		  k=1;
	  else
		  k=0;


	  x.units=x.units+N_units;
	  x.gradePoints=x.gradePoints+k*N_units;
	   
  }

  double gpa(Student &x)
  {
	 double GPA=(x.gradePoints)/x.units;
	  if(x.units==0)
		  return 0;

	  else
		  return  GPA;
  }
Last edited on
Zhuge (4664)
After you read in the input, you can use the string method find_first_not_of() to look for any characters not in a set you specify.
http://cplusplus.com/reference/string/string/find_first_not_of/
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