Set value into object with function (java script)

Question

When I used getFullName, getFirstName and getLastName work ok, but I can't use set functions setFullName, setLastName, setFirstName. My code:

var Person = function(firstAndLast) {
 var fn=firstAndLast.split(' ');
 var fstr=fn.join(' ');
 var frn=fn[0];
 var lsn=fn[1];
 this.getFullName=function(){return fstr;};
 this.getFirstName=function(){return frn;};
 this.getLastName=function(){return lsn;};
 this.setFirstName=function(a){fn[0]=a;};
 this.setLastName=function(b){fn[1]=b;};
 this.setFullName=function(c){fn=c.split(' ');};
};

• Bergi: You're setting fn[0], not frn

Answer 1

What about this:

var Person = function(firstAndLast) {
 var self = this;
 this.fn = firstAndLast.split(' ');
 this.frn = this.fn[0];
 this.lsn = this.fn[1];
 this.getFullName=function(){return self.fn.join(' ');};
 this.getFirstName=function(){return self.frn;};
 this.getLastName=function(){return self.lsn;};
 this.setFirstName=function(a){self.frn=a; self.fn[0]=a;};
 this.setLastName=function(b){self.lsn=b; self.fn[1]=b;};
 this.setFullName=function(c){
 self.fn = c.split(' '); 
 self.frn = this.fn[0];
 self.lsn = this.fn[1];};
};

See this fiddle

If you have a lot of Person objects, you should consider moving the getter/setter functions to the class prototype:

var Person = function(firstAndLast) {
 this.fn = firstAndLast.split(' ');
 this.frn = this.fn[0];
 this.lsn = this.fn[1];
};
Person.prototype.getFullName = function() {
 return this.fn.join(' ');
}
Person.prototype.getFirstName = function() {
 return this.lsn;
}
Person.prototype.getLastName = function() {
 return this.lsn;
}
Person.prototype.setFirstName = function(a) {
 this.frn=a; 
 this.fn[0]=a;
}
Person.prototype.setLastName = function(b) {
 this.lsn=b;
 this.fn[1]=b;
}
Person.prototype.setFullName = function(c) {
 this.fn = c.split(' '); 
 this.frn = this.fn[0];
 this.lsn = this.fn[1];
}

See updated fiddle