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const words = ["Beau", "Balle", "Ange",
"Ananas", "Reduce","Action"];
const alphabetical = words.reduce((a, x) => {
if(!a[x[0]]) a[x[0]] = [];
a[x[0]].push(x);
return a; }, {});
Object.keys(alphabetical).forEach(function (key) {
console.log(` ${key} => ${alphabetical[key]}`);
});
console.log(alphabetical);