如果一个字符串是一个字符数组，你如何将它转换成一个整数数组

Question

I kept getting an error with this loop. If there are something i missed, please help. Thank You!

int main(){
 string hasil;
 int cod[5];
 hasil = "99999";

 for(int i = 0; i < 5; i++){
     cod[i] = stoi(hasil[i]);
 }

 for(int i = 0; i < 5; i++){
     cout << cod[i] + 1;
 }

Answer 1

stoi is for converting entire strings to integers, but you're only giving it single characters.

You could either build strings from each character like so:

cod[i] = std::stoi(std::string(1, hasil[i])); // the 1 means "repeat char one time"

Or calculate the actual integer yourself using a bit of ascii math (assuming everything is a valid digit):

cod[i] = hasil[i] - '0'; // now '0' - '0' returns 0, '5' - '0' returns 5, etc...

Answer 2

std::stoi() takes a std::string , not a char . But std::string does not have a constructor that takes only a single char , which is why your code fails to compile.

Try one of these alternatives instead:

cod[i] = stoi(string(1, hasil[i]));

cod[i] = stoi(string(&hasil[i], 1));

string s;
s = hasil[i];
cod[i] = stoi(s);

char arr[2] = {hasil[i], '\0'};
cod[i] = stoi(arr);

Answer 3

The below complete working program shows how you can achieve what you want:

#include <iostream>

int main(){
 std::string hasil;
 int cod[5];
 hasil = "99999";

for(int i = 0; i < 5; ++i)
{
    cod[i] = hasil[i] - '0';
}

 for(int i = 0; i < 5; i++){
     std::cout << cod[i];
 }
 
 return 0;
}

The output of the above program can be seen here .

Answer 4

std::stoi only accpet std::string or std::wstring as an argument type. But hasil[i] is a char

In C++, '0' to '9' is guarantee to be ascending in ACSII values, so, you can do this:

cod[i] = hasil[i] - '0';