js .map in .map code example

Example 1: functions in map javascript

const map = new Map();

function foo() {
 return "Hello World!"; 
}

map.set("foo", foo);

console.log(map.get("foo")()); // Output: "Hello World!

Example 2: .map in js

// A function which returns the last character of a given string
function returnLast(arr) {
  return arr.at(-1);
}

let invoiceRef = 'myinvoice01';

console.log( returnLast(invoiceRef) );
// Logs: '1'

invoiceRef = 'myinvoice02';

console.log( returnLast(invoiceRef) );
// Logs: '2'