function counter(n) {
return {
get count() {
let nPlus = n++;
console.log('print get count():', nPlus);
return nPlus;
},
set count(m) {
if (m > n) n = m;
else throw Error('count can only be set to a larger value');
}
}
}
let c = counter(1000);
c.count;
c.count;
c.count=2000;
c.count;
c.count=2000;