Constants

int main() {
    int age = 16;
    int minDrinkingAge = 18;
    minDrinkingAge = 18 - 2;
    if(age >= minDrinkingAge) {
       cout << "Can buy alcohol" << endl;
    }
    return 0;
}
                    

int main() {
    const int minDrinkingAge = 18;
    minDrinkingAge--;  //compiler error
    return 0;
}
                    

int main() {
    int evenNum = 6;
    const int *luckyNum = &evenNum;
    *luckyNum = 10;    //compiler error
    return 0;
}
                    

int main() {
    int evenNum1 = 6;
    int evenNum2 = 12;
    const int *luckyNum = &evenNum1;
    evenNum1= 10;  //OK
    cout << "*luckyNum:" << *luckyNum << endl;
    luckyNum = &evenNum2;  //OK
    cout << "*luckyNum:" << *luckyNum << endl;
    return 0;
}
                    

int main() {
    int myAge = 20;
    int mumAge = 49;
    int *const dadAge = &mumAge;
    *dadAge = 50;  //OK
    cout << "mumAge:" << mumAge << endl;
    cout << "*dadAge:" << *dadAge << endl;
    mumAge = 51;   //OK
    cout << "mumAge:" << mumAge << endl;
    cout << "*dadAge:" << *dadAge << endl;
    dadAge = &myAge;   //compiler error
    return 0;
}
                        

int main() {
    int mumHomePh = 1111111;
    int *const myHomePh = &mumHomePh;
    int flatHomePh = 5555555;
    *myHomePh = 7777777;   //OK
    myHomePh = &flatHomePh;  //compiler error
    return 0;
}
                        

int main() {
    string primeCol = "red";
    const string &favCol = primeCol;
    cout << "primeCol: " << primeCol << endl;
    cout << "favCol: " << favCol << endl;
    primeCol = "blue";     //OK
    cout << "primeCol: " << primeCol << endl;
    cout << "favCol: " << favCol << endl;
    favCol = "green";    //compiler error
    return 0;
 }
                    

int main() {
    const string colour = "pink";
    string &favCol = colour;   //compiler error
    return 0;
}
                    

int main() {
    const string colour = "pink";
    const string &favCol = colour;    //OK
    colour = "black";    //compiler error
    favCol = "black";    //compiler error
    return 0;
}