replacing a character in a string

[grooviqw]

Hi
How can i replace a character from a introduced string?
let's say i introduce "aabcf"
i want to replace all a leters with b , so i introduce from the keyboard, that i want to replace a with b, what can i do next?
Here is my attempt :

#include <iostream>
#include <string>
using namespace std;
int main()
{
    string x;
    char y, t;
    int i;
    cout<<"The string is :  ";
    cin>>x;
    cout<< "The desired character is : ";
    cin>> x.at(i);
    for (i=0; i<x.length(); i++)
    {
        cin>> x.at(i);
    }
    cout<< "With what letter do you want to replace it : ";
    cin>>y;
    for (i=0; i<x.length(); i++)
    {
       t = x.at(i) == y;
    }
    cout<<t;

    return 0;
} 

[seeplus]

#include <iostream>
#include <string>
#include <algorithm>
using namespace std;

int main()
{
	string x;
	char y {}, d {};

	cout << "The string is: ";
	cin >> x;

	cout << "The desired character is: ";
	cin >> d;

	cout << "With what letter do you want to replace it: ";
	cin >> y;

	std::replace_if(x.begin(), x.end(), [&d](char c) {return d == c; }, y);

	cout << x;
}

The string is: aabcf
The desired character is: a
With what letter do you want to replace it: b
bbbcf

[grooviqw]

thanks

[grooviqw]

but if i want to replace just the characters "a" with b, and "b" with a, the other letters to remain the same?

[seeplus]

Only the specified desired character is replaced with the specified replacement letter. The others remain the same and are not changed.


Do you mean you want to do multiple replacements - eg c with d and e with h and z with y allwithin the same operation?

[grooviqw]

i mean if i introduce "aabbtt" to return "bbaatt"

[seeplus]

That is a multiple replacement - a with b, b with a

[seeplus]

include <string>
#include <iostream>
#include <map>

int main()
{
	std::map<char, char> repl;

	do {
		char oldc {}, newc {}, more {};

		std::cout << "Enter old char: ";
		std::cin >> oldc;

		std::cout << "Enter new char: ";
		std::cin >> newc;

		repl[oldc] = newc;

		std::cout << "More? (y/n): ";
		std::cin >> more;

		if (more != 'y')
			break;

	} while (true);

	std::string str;

	std::cout << "Enter string: ";
	std::cin >> str;

	for (auto& c : str)
		if (const auto f = repl.find(c); f != repl.end())
			c = f->second;

	std::cout << str << '\n';
}

Enter old char: a
Enter new char: b
More? (y/n): y
Enter old char: b
Enter new char: a
More? (y/n): n
Enter string: aabbtt
bbaatt

[grooviqw]

but without enter old char and new char, just enter string?

[seeplus]

OK

#include <string>
#include <iostream>
#include <map>

int main()
{
	const std::map<char, char> repl {{'a', 'b'}, {'b', 'a'}};

	std::string str;

	std::cout << "Enter string: ";
	std::cin >> str;

	for (auto& c : str)
		if (const auto f = repl.find(c); f != repl.end())
			c = f->second;

	std::cout << str << '\n';
}