Looping a Switch Case

Good day everyone, I'm new to C++ programming and was following the tutorials and came across a doozy in the switch ~ case tutorial. It said a loop function could be added to make the program wait for valid input, but with this code it just finishes the program no matter what the user inputs.

Code:

#include <iostream>

using namespace std;

int main()
{
    int input;
    
    cout<<"1. Play game\n";
    cout<<"2. Load game\n";
    cout<<"3. Multiplayer\n";
    cout<<"4. Exit\n";
    cout<<"Selection: ";
    cin>> input;
    

do {  // start loop
  
    switch ( input ) {  //start switch
    case 1:
         cout<<"Playing game...\n";
         break;
    case 2:
         cout<<"Loading game...\n";
         break;
    case 3:
         cout<<"Loading multiplayer server...\n";
         break;
    case 4:
         cout<<"Thanks for playing.\n";
         break;
    default:
            input = 0;                   // ==, !=, 
           }  // end switch
  
  }  while ( input = 0); //end loop, ==, !=,
    
    cin.get();  // a pause function to stop window from closing fast
    cin.get();
}

Is the loop code in the wrong place, or is the default part of the switch ~ case wrong?

My goal is to become a fairly decent programmer in the months (years, decades!) to come, and I feel pretty dumb not being able to figure this out.

= is different of ==. = means assign. == means check for equality.

Excellent! Well, as first impressions always last, I am now the greater of all idiots. What I did to fix the code was move the cin>> input into the loop command:

Code:

#include <iostream>

using namespace std;

int main()
{
    int input;
    
    cout<<"1. Play game\n";
    cout<<"2. Load game\n";
    cout<<"3. Multiplayer\n";
    cout<<"4. Exit\n";
    cout<<"Selection: ";
    
    

do {  // start loop
  
  cin>> input;
    switch ( input ) {  //start switch
    case 1:
         cout<<"Playing game...\n";
         break;
    case 2:
         cout<<"Loading game...\n";
         break;
    case 3:
         cout<<"Loading multiplayer server...\n";
         break;
    case 4:
         cout<<"Thanks for playing.\n";
         break;
    default:
            input = 0;                   // ==, !=, 
           }  // end switch
  
  }  while ( input == 0); //end loop, ==, !=,
    
    cin.get();  // a pause function to stop window from closing fast
    cin.get();
}