completed javascript assignment 6

Question1.js

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+/*
+Q1. Take the above array of objects. Accomplish the following tasks:
+Write a function filterByName that accepts a string as a parameter and returns
+an array with only those objects where the first_name field includes that 
+string.
+Use Array.map to return an array of all the email fields.
+Use Array.sort to return the array sorted in descending order by 
+  date_of_birth.
+Write a function getById that accepts a number as a parameter and returns 
+  the object where the id is equal to that number. 
+ */
+
+const employeeDetails = [
+  {
+    id: 1,
+    first_name: "Nicki",
+    email: "[email protected]",
+    date_of_birth: "2009/05/09",
+  },
+  {
+    id: 2,
+    first_name: "Raychel",
+    email: "[email protected]",
+    date_of_birth: "1996/11/05",
+  },
+  {
+    id: 3,
+    first_name: "Demetris",
+    email: "[email protected]",
+    date_of_birth: "2018/12/31",
+  },
+  {
+    id: 4,
+    first_name: "Amata",
+    email: "[email protected]",
+    date_of_birth: "2012/05/23",
+  },
+  {
+    id: 5,
+    first_name: "Venita",
+    email: "[email protected]",
+    date_of_birth: "2020/10/04",
+  },
+  {
+    id: 6,
+    first_name: "Fairfax",
+    email: "[email protected]",
+    date_of_birth: "2009/12/23",
+  },
+  {
+    id: 7,
+    first_name: "Kathleen",
+    email: "[email protected]",
+    date_of_birth: "2010/12/20",
+  },
+  {
+    id: 8,
+    first_name: "Sam",
+    email: "[email protected]",
+    date_of_birth: "2020/08/30",
+  },
+  {
+    id: 9,
+    first_name: "Virgilio",
+    email: "[email protected]",
+    date_of_birth: "2000/09/07",
+  },
+  {
+    id: 10,
+    first_name: "Townie",
+    email: "[email protected]",
+    date_of_birth: "2018/09/01",
+  },
+];
+
+const filterByName = (name) => {
+  let reqEmployees = employeeDetails.filter((emp) =>
+    emp.first_name.includes(name)
+  );
+  return reqEmployees;
+};
+
+console.log(filterByName("Nic"));
+
+const getEmailIds = () => employeeDetails.map((emp) => emp.email);
+
+console.log(getEmailIds());
+
+const sortByDate = () => {
+  return employeeDetails.sort((emp1, emp2) => {
+    const date1 = new Date(emp1.date_of_birth);
+    const date2 = new Date(emp2.date_of_birth);
+
+    return date2 - date1;
+  });
+};
+
+console.log(sortByDate());
+
+const getById = (inputId) => {
+  return employeeDetails.filter((emp) => emp.id === inputId);
+};
+
+console.log(getById(1));

Question2.js

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+/*
+2. What makes a method mutating or non mutating in Javascript?
+Find out whether each of the following methods are mutating or non-mutating.
+How can you verify this?:
+
+push
+pop
+filter
+find
+sort
+map
+*/
+
+/*
+Mutating methods-
+Methods which make changes in same array, without creating new ones.
+Eg:-
+.push() — Adds a new item as the last item of the array.
+.pop() — Removes the last item of the array.
+.unshift() — Adds a new item as the first item of the array.
+.shift() — Removes the first item of the array.
+.reverse() — Reverses the order of the array.
+.splice() — Removes/replaces item(s) in the array.
+.sort() — Re-orders the items in the array based on their Unicode code points.
+.copyWithin() — Copies one part of the array and puts it on another part of the same array.
+.fill() — Changes some or all items in the array into the value being passed in.
+
+Non-Mutating-
+Methods which returns new array as result.
+Eg:-
+.filter()-creates new array on the basis of given condition 
+.find()-returns the first index of the given element that satisfies the condition
+.map()-returns the new array by applying the various operation given to it.
+
+*/