Why the getline function is not working in if statement ?

Question

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if i am writing the following code then at run time the code is not asking for the string and it takes only the value of number, why it is?

C++

#include<iostream.h>
#include<fstream.h>
#include<conio.h>

class x
{
      char ch[30];
      int num;
      public:
             void getdata()
             {
                  cout<<"Enter string";
                  cin.getline(ch,30);
                  cout<<"Enter a number :";
                  cin>>num;    
             }
};

int main()
{
    x o;
    int choice;
    cout<<"Enter your choice 1 for getdata and 2 to exit";
    cin>>choice;
    if(choice==1)
                 o.getdata();
    else
                 exit(0);
    getch();
    return 0;
}

[edit]Code block added, html encoded - OriginalGriff[/edit]

Posted 5-Apr-12 19:55pm

Ashutosh_g

Updated 5-Apr-12 20:05pm

v3

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3 solutions

Solution 2

This may be due to a '\n' left in the stream from some other part of your program. Flush the stream before using getline(). What chandanadhikari suggested is absolutely right. Try using cin.ignore() or cin.sync and cin.clear ,your problem will be solved.

C++

class x
{
      
	
        char ch[30];
        int num;
        public:
	
             void getdata()
             {
				 
	         cout<<"Enter string:\n";
                  cin.ignore(); 
		getline(cin,s);
                  cout<<"Enter a number :";
                  cin>>num;    
				  
             }
};

Posted 5-Apr-12 23:09pm

Member 8576081

Solution 3

check if using, cin.clear() and cin.sync() after the number is entered helps.

Posted 6-Apr-12 0:06am

PerlongFiona

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chandanadhikari · Accepted Answer · 2012-04-05T20:56:00

Solution 1

hi,
use cin.ignore() before cin.getline() and tell what happens .
also you can check if using, cin.clear() and cin.sync() after the number is entered helps.

Posted 5-Apr-12 20:56pm

chandanadhikari