class Person {
    // add static
    static isHuman = true;
    constructor(name) {
        this.name = name;
    }

    speak() {
        console.log('Hello this is ' + this.name);
    }
}

// create pooya iliya
const pooya = new Person('Pooya');
const iliya = new Person('iliya');

// log
console.log(pooya.isHuman);
console.log(iliya.isHuman);
console.log(Person.isHuman);