Entering 5 names into a 2D Array

[pauyon]

Hello everyone,

I need to make a 2D Array that can hold 5 student names (including last names) that is imputed manually by the person when asked. Now I kind of have and idea to initialize an array like this;

const int maxNames=5;
const int maxChar=20;
char students[maxNames][maxChar];
cout<<"Enter the names of five students:"<<endl;

That's how far I have gotten. I don't know how I would go about to accept a name and store each name in a separate row. I also need to know how I could print the names too, just so I can see if they have been stored. One more thing, I don't know how to use vectors yet, so if you know how to do this without using vectors I'd appreciate the help. Thanks in advanced.

[Athar]

If you don't know about vectors yet, you should remedy that.
Even without a vector, you can at least use std::string:

const int maxNames=5;
string students[maxNames];

If you absolutely insist on using a 2D char array, you can use strcpy to copy names into the array:

int currentIndex=0;
strcpy(students[currentIndex++],name);

[pauyon]

I'll try that, and would I need a "nested loop" to enter the names or? And also, would the command "cin>>" still work for it to enter the names?

const int maxNames=5;
const int maxChar=20;
string students[maxNames][maxChar];
for( int i=0; i<maxChar; i++)
      cin>>student[i][maxChar];

Yeah, I can't do vectors since I haven't learned about them yet, but they're coming up soon so I can't wait for that chapter haha.

[LB]

If you're using strings you can just do this:

const unsigned int MaxNames = 5;
string Students[MaxNames];
for(unsigned int i = 0; i < MaxNames; ++i)
{
	cout << "Enter student " << i + 1 << "'s name: ";
	cin >> Students[i];
}

[Zhuge]

LB++, except I would use getline() instead of cin>>.

[pauyon]

Do I just put string next to the variable? How would I set it up?

[pauyon]

Remember this need to be a 2D Array. [5][20] :

[Lv0f92yv]

I agree with the first couple posters that strings would be the more straightforward way to do it. But to answer your question on looping for input using a 2D array:

#include <iostream>
using namespace std;

int main()
{
	char sentence[5][20] ;

	for ( int i = 0; i < 5; i++ )
	{
		cout << "\nEnter sentence: ";
		cin.getline( sentence[i], 20 );
	}

	for ( int i = 0; i < 5; i++ )
	{
		cout << sentence[i] << "\n";
	}
}

Loop for a line for every index of your character array. Each indice points to a string of characters (char*).

[pauyon]

Alright I guess I made some progress haha. I was able to imput the names into the arrays, but when I "nest" loop to print the names, the names print but up to a certain point before they become some weird symbols and y's.

[Lv0f92yv]

Sounds like your accessing memory that your program doesn't own. This happens, for example, in the following case:

char letters[5];
cout << letters[6]; //on some platforms this crashes, others is just prints garbage 

What loop are you using? I don't think there is a need for any nested loops using the 2D array example... Unless you want to print one char at a time, in which case it would look something like this:

#include <iostream>
using namespace std;

int main()
{
	char sentence[5][20];

	for ( int i = 0; i < 5; i++ )
	{
		cout << "\nEnter sentence: ";
		cin.getline( sentence[i], 20 ); //this null-terminates the array of chars by placing a '\0' at the end of the stream
	}

	for ( int i = 0; i < 5; i++ )
	{
		for ( int j = 0; j < 20; j++ )
		{
//check to see if we hit the end of the string
			if ( sentence[i][j] != '\0' )
				cout << sentence[i][j];
			else
			{
				cout << "\n"; //formatting
				break; //stop printing past null terminator (garbage chars)
			}
		}
	}
}

[pauyon]

Ah wait, I ended up getting them to print! Haha thanks ......I just don't know why they would ask for a 2D array... couldn't I have just made a 1D array and go the same results??

[Lv0f92yv]

A 1D character array would only allow you to store one "string". Each element in the array would be a character, together which would comprise your "string".

A 1D array of strings can be thought of the same thing (it's not, really) as a 2D char array, since each string object in the array of strings itself contains an array of characters.

[pauyon]

Ooh... I see now... thanks for the clarification! Looks like they aren't as hard as they seem..