[Solved] Reversing using loop

[ChocolateColumbo]

Hello all. So far I know how to reverse a string through obvious methods like var.rbegin(), var.rend(), but I would like to know how to do the same thing but using a loop. So far I have the code below and I can get the program to read back the first character of the string. I would like it to reverse and read back the whole string but I am unsure how to do that. If any of you could instruct me on how to do it I would appreciate it very much. Also if any of you can tell me how to assign a string to an array I would also appreciate that. The commented out portion has been my attempt so far. Thank you.

  #include<iostream>
#include<string>
#include<locale>
std::string reverse(std::string a)
{
int z,  y;
z=a.length();
y=.5*z;
/*char a1[]={};
a1[1]=z;
*/
for(int x=0; x<y; ++x)
{

std::cout << a[z-1]<<std::endl;
}


return a;
}

int main()
{
std::string b;
std::cout<<"Enter string: ";
std::getline(std::cin, b);
reverse(b);

return 0;
}

[jgg2002]

It's quite easy actually. You just need to iterate the string starting from the end and finishing at the place 0 of the string. Also, you need to have another string variable for saving each element.

Pseudocode (sort of)

declare stringa
declare stringb
strinb = stringa
for i = length of stringa-1 i>=0 i decreases by one
stringb element in place length of stringb - 1 = stringa element in place i
output stringb

Here it is in C++

#include<iostream>
#include<string>

using namespace std;

string reverse(string str){
    int len = str.size()-1;          //the size of the array, i just put it in a variable to clear the code
    string temp=str;                //declare a temporary string
    for (int i=len; i>=0; i--){
        temp[len-i]=str[i];          //here, i starts from the end of the string, finishes at 0. So, 
                                             //when i = len, then len-i=0 So temp[0] = temp[len]
                                             //first equals final. the second equals second from the end
                                             //and so on
    }
    return temp;
}

int main(){
    string input;
    getline(cin, input);
   cout<<reverse(input);
}

Now, assign a string to an array:

Strings are already 1D arrays of characters. If I understood correctly, you need an array of strings, right? So this s a 2D array. This can be done easily, example below:

Example: Make a program which gets as an input in the first line an integer N (number of students) and then a number K<N which defines which student in the list to output. After, N lines, each of a name of a student. This is a simple array problem. If it was with integers, not names it would be:

#include<iostream>
using namespace std;

int main(){
int n;
cin>>n;
int place;
cin>>place;
int arr[n];
for (int i=0; i<n; i++){
cin>>arr[i];
}
cout<<arr[place-1]; //-1 because of the index starting from 0
}

With strings it's quite similar:

#include<iostream>
#include<strings>
using namespace std;

int main(){
int n;
cin>>n;
int place;
cin>>place;
string names[n];          //declare an array of strings
for (int i=0; i<n; i++){
cin>>names[i];
}
cout<<names[place-1];
}

If you want to acces a letter of a string in a string array, such as the student's first letter:

names[place-1][0];

[ChocolateColumbo]

That is exactly what I was trying to do. Thank you very much. I had been stumped for a while.