Thread: Reversing a string

Search the forum. This question gets posted all the time.

Code:

void revstr( void )
{
    char c;
    std::cin >> c;
    if( c != '\n' )
        return;
    revstr( );
    std::cout << c;
}

You likely will not want to use this for your homework example, unless you can actually explain to your instructor exactly what's happening. If you can't, then you'll want to search the forum for a "real answer".

Quzah.

Well, if you are allowed to use some of the standard template library items, there are some very easy ways to do this. Also, you could create a stack and push each character on it, then pop them all back off once they hit enter or what not, and display them that way. Using STL, you could easily use a vector or something nifty to do this.

However, I suspect they have something a bit more simplistic in mind. Something like:

1) Declare a huge buffer.
2) Start a counter.
3) Read characters into the buffer, incrementing the counter.
4) When they enter a new line (enter on the keyboard), stop reading into the buffer.
5) Since the counter will point at the end of the buffer, start there, and decrement the counter, displaying the contents of the buffer in reverse.

By "buffer", in this case, you'd just likely use an array.

Quzah.

If your interested in the stack method, I'd recommend an STL list.

You can use the push_front(item), front(), and pop_front() methods to make it behave just like a stack.

I'd suggest using the string library. Here's a basic program that utilizes it.

Code:

#include <iostream>
#include <string>

using namespace std;

int main()
{
	string word;
	cout << "Enter a word: ";
	cin >> word;
	cout << "The length of " << word << " is: " << word.size() << '\n';
	cout << "The first character is: " << word[0] << '\n';
	cout << "The last character is: " << word[word.size()-1] << '\n';
	return 0;
}

I'll leave the logic up to you.

Originally posted by ygfperson
shouldn't it be c == '\n'? Otherwise it would just return for any string...

Yep. Typo. It had it right first, but I changed how the function worked. Then I didn't like it, so I changed the rest of the function back, and forgot that line.

[edit]
The code I was going to use was:

Code:

void revstr( void )
{
    char c;
    std::cin >> c;
    if( c != '\n' )
        revstr( );
    std::cout << c;
}

But I didn't like it, because it would have output the newline character, which I didn't like.
[/edit]

Quzah.

I must say, that is quite clever. I would've gone straight for the loop.