std::string::replace “没有匹配的 function for call”错误

Question

I really don't know how to make this program work correctly. The only problem at the moment is the replace . I can't get it to work. What am I doing wrong with it? We're only allowed to use if - else , and while statements.

#include <iostream>
#include <string>

using namespace std;

int main() {

   /*i becomes !
     a becomes @
     m becomes M
     B becomes 8
     o becomes .
     append q*s */

   string passWord;

   cin >> passWord;

   char chari = 'i';
   int strLen = passWord.length();
   int curPos = 0;
   int chariIndex = passWord.find(chari);

   while (curPos < strLen) {
      if (passWord.find(chari)) {
         passWord.replace(chariIndex, 1, '!');
         cout << chariIndex << endl;
         curPos += 1;
      } 
   }

   cout << passWord << endl;
   return 0;
}

Answer 1

You are not calling any of the overloads of std::string::replace . However, since you are only replacing a single character, instead of replace , you could simply do

passWord[chariIndex] = '!';

If you want to use replace then you could call it like this:

passWord.replace(chariIndex, 1, "!");

Note that the 3rd argument is a string , not a char .

Also, std::string::find does not return a bool , as you seem to be expecting in your code. You need to compare the result of find to std::string::npos instead:

if (passWord.find(chari) != std::string::npos) {
  // found

If you use the result of find as a bool , it will always evaluate to true (unless you find the character at the 0th index).