A function that replaces a character in a given string with another.

replacestring.cpp

#include <string>
using namespace std;

/**
 *      Replaces every occurance of repchar with newchar in the str
 * and returns a copied value.
 * @param[in] str The string who's characters are being replaced.
 * @param[in] repchar The character to replace.
 * @param[in] newchar The character to replace with.
 * @param[out] The copied string with replaced characters.
 */
string replacechar(string str, char repchar, char newchar) {
    string replacedstr;
    
    /**
     *      Copy the characters one by one into the new string
     * but if the character being copyed needs to be replaced
     * then insert the replaced character instead.
     */
    for (uint32_t charindex = 0u; charindex < str.length(); charindex++) {
        char currchar;
        
        currchar = str.at(charindex);
        if (currchar == repchar) {
            replacedstr.push_back(newchar);
        } else {
            replacedstr.push_back(currchar);
        }
    }
    
    return replacedstr;
}