Reformat shitty api

A. Reformat shitty api.md

Reformat shitty api

index.ts

const dataSet = [{
    datetime: "January 3rd 1999 at 15:34 UTC",
    location: 3,
    animal: { isMammal: true, }
  },
  {
    datetime: "January 3rd 1999 at 15:34 UTC",
    location: 4,
    animal: { isMammal: true, }
  },
  {
    datetime: "January 3rd 1999 at 15:34 UTC",
    location: 4,
    animal: { isMammal: false, }
  },
  {
    datetime: "January 4th 1999 at 15:34 UTC",
    location: 4,
    animal: { isMammal: false, }
  },
  {
    datetime: "January 5th 1999 at 15:34 UTC",
    location: 6,
    animal: { isMammal: true, }
  },
];

// TODO: Could be better with a Map()?
const mammalPercentages = (observations) => {
  const formattedDataSet = observations.reduce((acc, cur) => {
    const dateKey = cur.datetime.split('at')[0].trim(); // could use getUTCDate?
    if (!acc[dateKey]) {
      acc[dateKey] = {};
    }
  
    if (! acc[dateKey]["observations"]) {
      acc[dateKey]["observations"] = [];
    }
  
    let obsForLoc = acc[dateKey]["observations"].find(el => el.location === cur.location);
  
    if (!obsForLoc) {
      acc[dateKey]["observations"].push({
        location: cur.location,
        animals: [],
      })
    }
  
    obsForLoc = acc[dateKey]["observations"].find(el => el.location === cur.location);
    obsForLoc["animals"].push(cur.animal);
  
    return acc;
  }, {});
  
  
  const ratio = (arrayOfObservation) => {
    const mamals = arrayOfObservation.filter((o) => o.isMammal);
    return mamals.length / arrayOfObservation.length * 100;
  }
  
  return Object.entries(formattedDataSet).forEach((entry) => {
    return entry[1].observations.forEach((obs) => {
      console.log(
        `On ${entry[0]}, for location ${obs.location}, ${ratio(obs.animals)}% of animals were mamals`
      );
    })
  })
}

mammalPercentages(dataSet);
// prints: 
// On January 3rd 1999, for location 3, 100% of animals were mamals
// On January 3rd 1999, for location 4, 50% of animals were mamals
// On January 4th 1999, for location 4, 0% of animals were mamals
// On January 5th 1999, for location 6, 100% of animals were mamals