Catalogue

function catalogue(input) {

    let products = [];

    for (let i = 0; i < input.length; i++) {
        products.push(input[i].split(" :")
            .join(":"));
    }

    products.sort((a, b) => a.toLowerCase()
        .localeCompare(b.toLowerCase()));

    let firstLetter = "";
    for (let product of products) {
        if (firstLetter !== product.charAt(0)) {
            firstLetter = product.charAt(0);
            console.log(firstLetter);
        }

        console.log("  " + product);
    }
}