help with fgets

**grumpy** · 06-08-2009

Ah the joys of people being given code without an explanation of what it does.

Any basic texts on C++ (even the really bad ones) will cover this stuff in the first few chapters. Just read them from the beginning.

:: is the scoping operator. So the name X::Y means something named Y within a namespace (literally a universe of names) named X. So std::getline refers to something named getline in the std namespace. The std namespace is reserved for use by compilers and libraries .... basically so, if a programmer needs to, something called getline can be created in another namespace without clashing.

The >> and << are operators. They have multiple meanings. For integer types, they are bitshift operators. When working with C++ I/O streams, which is how you're working with them, the syntax "some_output_stream << x" means that a variable s is written out to the specified output stream - << is called things like the "stream insertion operator". The syntax "some_input_stream >> x" means a value of x is extracted from the input stream, and >> is referred to as something like the "stream extraction operator".

**n3cr0_l0rd** · 06-08-2009

one final question.. that means using

Code:

std::getline()

and

Code:

getline()

means the same or different... ?

**n3cr0_l0rd** · 06-08-2009

hope the above question was not stupid attempt of me trying to act as not stupid at all :P

**laserlight** · 06-08-2009

In this context std::getline and getline refer to the same function since the using directive, using namespace std, is in effect.

**Elysia** · 06-08-2009

You need a good beginner's book for C++. I recommend Accelerated C++.
Very informative. Very good.
You will be ready to do good C++ programs afterwards (not just basics!).

**n3cr0_l0rd** · 06-09-2009

yeah... great book for me.. m reading it atm... thx for that

**n3cr0_l0rd** · 06-09-2009

Code:

// Input your full name and put it in a frame
#include <iostream>
using namespace std;

int main()
{
	cout<<"Enter your full name : ";
	string name;
	getline(cin,name);
	const string greet = "Hello, " +name+"!";
	const string spaces(greet.size(),' ');
	const string second = "* "+spaces+" *";
	const string first(second.size(),'*');
	cout<<"\n\n"<<first<<endl;
	cout<<second<<endl;
	cout<<"* "<<greet<<" *"<<endl;
	cout<<second<<endl;
	cout<<first<<endl;
	system("pause");
return 0;
}

I wrote it on my own without looking at the codes.... I am really enjoying reading that book... CHeers

**n3cr0_l0rd** · 06-09-2009

When i looked back into the codes in that book, it had included <string> header file too... But why? I couldnt get it why? The original code in the book:

Code:

// ask for a person's name, and generate a framed greeting
#include <iostream>
#include <string>
int main()
{
 std::cout << "Please enter your first name: ";
 std::string name;
 std::cin >> name;
 // build the message that we intend to write
 const std::string greeting = "Hello, " + name + "!";
 // build the second and fourth lines of the output
 const std::string spaces(greeting.size(), ' ');
 const std::string second = "* " + spaces + " *";
 // build the first and fifth lines of the output
 const std::string first(second.size(), '*');
 // write it all
 std::cout << std::endl;
 std::cout << first << std::endl;
 std::cout << second << std::endl;
 std::cout << "* " << greeting << " *" << std::endl;
 std::cout << second << std::endl;
 std::cout << first << std::endl;
 return 0;
}

**tabstop** · 06-09-2009

Originally Posted by n3cr0_l0rd

When i looked back into the codes in that book, it had included <string> header file too... But why? I couldnt get it why? The original code in the book:

Because it is not possible to use a string in a program without including the string header.

**Elysia** · 06-09-2009

std::string resides in the <string> header. That mentioned, however, sometimes one header can have dependencies on another - such as iostream dependent on <string>, thus you can sometimes get a header for "free".
This is not something you should rely on.

**n3cr0_l0rd** · 06-10-2009

@Elysia Thx, i get it... You are really too great

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