Catalogue

function catalogueFun(input) {

                let catalogue = [];
                input
                    .forEach((line) => {
                        let tokens = line.split(' : ');
                        let productName = tokens[0];
                        let productPrice = Number(tokens[1]);
                        let item = productName + ': ' + productPrice;
                        catalogue.push(item);
                    });
                catalogue.sort((a, b) => a.localeCompare(b));
                let letters = [];
                for (let i = 0; i < catalogue.length; i++) {
                    let firstLetter = catalogue[i][0];

                    if (!letters.includes(firstLetter)) {
                        letters.push(firstLetter);
                    }
                }
                for (let j = 0; j < letters.length; j++) {
                    console.log(letters[j]);
                    let result = catalogue.filter((item) => item[0] === letters[j]);
                    result.forEach((el) => {
                        console.log(el)
                    });
                }
            }