js can we use functions in a class code example

Example 1: javascript new function as class

// Javascript Function that behaves as class, with private variables
function Person(name){
    const birth = new Date();
    this.greet = () => `Hello my name is ${name}. I was born at ${birth.toISOString()}`;
}

const joe = new Person("Joe");
joe.greet(); // Hello my name is Joe. I was born at 2021-04-09T21:12:33.098Z
// The birth variable is "inaccessible" from outside so "private"

Example 2: Using functions in Class

class Student{
    int scores[5];
    public:
    void input(){
        for(int i=0; i<5; i++){
            cin >> scores[i];
        }
    }
    int calculateTotalScore(){
        int total = 0;
        for(int i=0; i<5; i++){
            total += scores[i];
        }
        return total;
    }
};