编辑代码

var Person =  function(firstAndLast){
    this.getFirstName= function(){ return firstAndLast.split(" ")[0]} ,
    this.getLastName=function(){return firstAndLast.split(" ")[1]} ,
    this.getFullName= function(){ return firstAndLast;} ,
    this.setFirstName= function(first){ firstAndLast=first+" "+firstAndLast.split(" ")[1]; } ,
    this.setLastName= function(last){firstAndLast=firstAndLast.split(" ")[0]+" "+last; } ,
    this.setFullName=function(full){    
      firstAndLast=full;
    }
};

var bob = new Person('Bob Ross');
console.log(bob.getFullName());
bob.setFirstName("Ann")
console.log(bob.getFullName());