12 days of Christmas.js

// Oh No!

// The song sheets have been dropped in the snow and the lines of each verse have become all jumbled up.

// Task
// You have to write a comparator function which can sort the lines back into their correct order, otherwise Christmas will be cancelled!

// Reminder: Below is what the final verse should look like

// On the 12th day of Christmas my true love gave to me
// 12 drummers drumming,
// 11 pipers piping, 
// 10 lords a leaping, 
// 9 ladies dancing, 
// 8 maids a milking,
// 7 swans a swimming, 
// 6 geese a laying, 
// 5 golden rings, 
// 4 calling birds,
// 3 French hens, 
// 2 turtle doves and 
// a partridge in a pear tree.

var comparator =(a,b)=> (+b.match(/\d+/)- (a[0]== 'O'? 1:0))- (+a.match(/\d+/)- (b[0]== 'O'? 1:0))