sizebeginnerconst m = new Map([['a', 1], ['b', 2]])
console.log(m.size) // β 2
m.set('c', 3)
console.log(m.size) // β 3Read Map.size to get the number of key-value pairs in the map.
Deleting an entry decreases the size.
Challenge: Verify that after delete(), size decreases.