在javascript中的函数内访问实例变量？

function Person(name, age) {
  this.name = name; // 实例变量
  this.age = age; // 实例变量

  this.sayHello = function() {
    console.log("Hello, my name is " + this.name + " and I am " + this.age + " years old.");
  }
}

var person1 = new Person("John", 25);
person1.sayHello(); // 输出：Hello, my name is John and I am 25 years old.