var map1 = new Map();
map1.set('a', 'alpha');
map1.set('b', 'beta');
map1.set('g', 'gamma');
console.log(map1.size);
// expected output: 3
var map1 = new Map();map1.set('a', 'alpha');map1.set('b', 'beta');map1.set('g', 'gamma');console.log(map1.size);// expected output: 3