Answers for "group array of object by key"

javascript group by property array of objects

function groupArrayOfObjects(list, key) {
  return list.reduce(function(rv, x) {
    (rv[x[key]] = rv[x[key]] || []).push(x);
    return rv;
  }, {});
};

var people = [
    {sex:"Male", name:"Jeff"},
    {sex:"Female", name:"Megan"},
    {sex:"Male", name:"Taylor"},
    {sex:"Female", name:"Madison"}
];
var groupedPeople=groupArrayOfObjects(people,"sex");
console.log(groupedPeople.Male);//will be the Males 
console.log(groupedPeople.Female);//will be the Females

how to group an array of objects

const groupBy = (array, key) => {
  // Return the end result
  return array.reduce((result, currentValue) => {
    // If an array already present for key, push it to the array. Else create an array and push the object
    (result[currentValue[key]] = result[currentValue[key]] || []).push(
      currentValue
    );
    // Return the current iteration `result` value, this will be taken as next iteration `result` value and accumulate
    return result;
  }, {}); // empty object is the initial value for result object
};