Javascript Constructor - Use An Object?

I'm trying to create a new object by using an already made object. This is what I am trying to achieve: var obj = {'Name' : 'Patrick', 'Age': 25, 'Country': 'US'}; document.writeln

Solution 1:

You have plenty of options here.

For example you could make your Person polymorphic on arguments it takes.

functionPerson(name, age, country) {
   if(arguments.length === 1 && typeof name === 'object') {
      var data = arguments[0];
      name = data.name; //etc
   } 
   //the rest of ctor code goes here
}

Or BETTER use factory function and keep your constructor code as simple is possible

functioncopyPerson(obj) {
   returnnewPerson(obj.name, obj.age, obj.country);
}

//or evenPerson.copy = function(obj) {
   returnnewthis(obj.name, obj.age, obj.country)
}

Solution 2:

This is what you could do to support both the input formats:

   function Person(name, age, country) {
        var obj;
        if(typeof(name) === 'object'){
          obj = name;
          name = obj.name;
          age = obj.age;
          country = obj.country;
        }
        this.name = name;
        this.age = age;
        this.country = country;
    }

Solution 3:

var Person = function(nameOrObj, age, country) {
  if (typeof nameOrObj === 'object') {
    this.name = nameOrObj.name
    this.age = nameOrObj.age
    this.country = nameOrObj.country
  } else {
    this.name = nameOrObj
    this.age = age
    this.country = country
  }
}