do while loop c++ loops continuously

//vars
int A; //any variable will do

// loop
do {
  A = 0; // clearing last input from last looping
  cout << "request value for A";
  cin >> A;
  
}
while (A != 'any value other than zero');

do {
   // codes;
}
while (testExpression);

while(/*Expression*/){
 //Statements go here
}