What is map.get() method in TypeScript?

// create some Maps 
let evenNumbers = new Map<string, number>([["two", 2], ["four", 4], ["eight", 8]])
let cart = new Map<string, number>([["rice", 500], ["bag", 10]])
let countries = new Map<string, string>([["NG", "Nigeria"], ["BR", "Brazil"], ["IN", "India"]])
let isMarried = new Map<string, boolean>([["James", false], ["Jane", true], ["Doe", false]])
let emptyMap = new Map<null, null>()
// get some values
console.log(evenNumbers.get("two"))     // 2
console.log(cart.get("books"))          // undefined
console.log(countries.get("IN"))        // India
console.log(isMarried.get("James"))     // false   
console.log(emptyMap.get(null))         // undefined