question on gets()

[Mishu]

In the following program if i reverse the order of the two i/o statements,that is,if i enter the number of elements first and after that the string..the command prompt doesnt takes in the string...why is it so?

#include <iostream>
#include <stdio.h>
using namespace std;
int main()
{
char arr[10];
int n;
cout<<"Enter string "<<endl;
gets(str);
cout<<"Enter the number of elements"<<endl;
cin>>n;
}

[Aceix]

Basically the cin object reads characters until a newline(return/enter) character is reached. So if its not giving you the chance then you might want to ignore any newline character in the buffer using the cin.ignore(); function before reading from the buffer.

Better still why don't you replace the gets() function with the standard cin? as it C++?
Also, there is no need for the <stdio.h> better still <cstdio> header as its C and not C++ -- This should be done after removing the gets() function.

Aceix.

[Z e r e o]

Aceix wrote:

Basically the cin object reads characters until a newline(return/enter) character is reached.

That is not correct. std::cin will not read up until a newline is hit it will read up until the first whitespace is hit. If you want to read up until a newline you should use getline() instead.


As for the OP's question.

Could you explain a bit more about your problem? Not exactly sure what you mean by switching the two IO statements around. Do you mean do this instead?

cout<<"Enter the number of elements"<<endl;
cin>>n;
cout<<"Enter string "<<endl;
gets(str);

NOTE: Where is the variable str defined?

Also as Aceix mentioned I would suggest not mixing C and C++ IO operations. If you are going to use C++ might as well use it's IO operations (Specially since you are already for the integer).

[Smac89]

Apart from the obvious being that there is a stray newline character still in the input buffer, there is also the case of what happens at runtime when the user of your program decides to enter a string larger than 9 characters (buffer overflow):

http://coliru.stacked-crooked.com/a/a799e84bfe22bf7c

[Mishu]

sry it was gets(arr) and not str

[Mishu]

got it..tnx alot