Storage - fundamentals

function solve(input) {
  let map = new Map();
  for (let string of input) {
    let tokens = string.split(' ');
    let product = tokens[0];
    let quantity = Number(tokens[1]);
    if (!map.has(product)) {
      map.set(product, quantity);
    } else {
      let currQuantity = map.get(product);
      let newQuantity = currQuantity += quantity;
      map.set(product, newQuantity);
    }
  }
  for (let key in map) {
    console.log(`${key} -> ${map[key]}`);
  }
}