js object添加方法

let person = {
    firstName: "John",
    lastName: "Doe",
    fullName: function() {
        return this.firstName + " " + this.lastName;
    }
};

console.log(person.fullName()); // 输出: John Doe

function Person(firstName, lastName) {
    this.firstName = firstName;
    this.lastName = lastName;
}

Person.prototype.fullName = function() {
    return this.firstName + " " + this.lastName;
};

let person1 = new Person("Jane", "Doe");
console.log(person1.fullName()); // 输出: Jane Doe

function Person(firstName, lastName) {
    this.firstName = firstName;
    this.lastName = lastName;
    this.fullName = function() {
        return this.firstName + " " + this.lastName;
    };
}

let person2 = new Person("Jim", "Beam");
console.log(person2.fullName()); // 输出: Jim Beam

function Person(firstName, lastName) {
    this.firstName = firstName;
    this.lastName = lastName;
}

Person.prototype.fullName = function() {
    return this.firstName + " " + this.lastName;
};