Getting a number when added char. Why? [duplicate]

Question

I am trying to concatenate the characters of a string but getting numerical value(s) instead. Why's that so?

C#

using System;

namespace std {
    class Program {
        static void Main(string[] args) {
            string n = "helloWorld!";
            Console.WriteLine(n[0] + n[1] + n[2] + n[3] + n[4] + n[5]);
        }
    } 
}

C++

#include <iostream>
using namespace std;

int main() {
    string x = "helloWorld!";
    cout << x[0] + x[1] + x[2] + x[3] + x[4] + x[5] << endl;
    return 0;
}

Output(Both languages) -

619

Expected Output -

helloW