1 function counter(n){ //Function argument n is the private variable 2 return{ 3 //Property getter method returns and increments private counter var. 4 get count(){return n++;}, 5 //Property setter doesn't allow the value of n to decrease 6 set count(m){ 7 if(m>=n)n=m; 8 else throw Error("count can only be set to a larger value"); 9 } 10 }; 11 } 12 var c=counter(1000); 13 c.count;//=>1000 14 c.count;//=>1001 15 c.count=2000; 16 c.count;//=>2000 17 c.count;//throw error