[Reduce, map, filter, slice] #js

gistfile1.txt

function toList(stockedList)

// Grocery store lab

const data = [
  ['apples', 73],
  ['pears', 12],
  ['oranges', 97],
  ['grapes', 387],
  ['grapes', 88],
  ['pears', 33],
  ['apples', 75],
  ['grapes', 23],
  ['oranges', 86],
  ['kiwis', 201]
];

// ######### REDUCE
// reduce can return anything, not just an array ect
// use reduce to reduce down a data type you dont like or want to change
// reduce iterates through the data array doing a function
function countFruit(data) {
  // fruitlist is the 'accumulater' it takes each pass and builds it into a new array
  return data.reduce((fruitList, currentItem) => {
    // if "apple" is in the entire array (apple is list.currentitem(which will be whatever key this time through))
    if (fruitList[currentItem[0]]) {
      //if "apple" does exist, then att the currentitem[1] (number) to the key
      fruitList[currentItem[0]] += currentItem[1]
    } else {
      fruitList[currentItem[0]] = currentItem[1]
    }
    return fruitList;
  }, {});
}                
        

const countedFruits = countFruit(data);
const objectCountedFruits = Object.entries(countedFruits)


// ####### map
// map iterates an array and creates a new array with the listed parameters
function stockUp(data, stockNumber){
  const stockedUpList = { ...data };
  Object.keys(stockedUpList).forEach(fruit => {
    stockedUpList[fruit] += stockNumber;
  });
  return stockedUpList;
}
      

var stockedList = stockUp(countedFruits, 51);

function explain(data) {
  let fruits = "";
  Object.keys(data).forEach(fruit => {
    fruits += `${data[fruit]} ${fruit}`;
  });
  return fruits.substring(0, fruits.length -2);
}