SOURCE

function Person(name){
  this.name=name;
  this.age=0;
  this.sex='male';
  this.married=0;
  
  this.say=function(){
    return 'my name is '+this.name;
  }
  this.sayLove=function(lover){
    return 'I love '+lover;
  }
}

var mike=new Person('Mike');
mike.age=18;
mike.married=1;
console.log(mike.name);
console.log(mike.age);
console.log(mike.sex);
console.log(mike.married);
console.log(mike.say());
console.log(mike.sayLove('Snow'));