Objects

1. Write functions for working with shapes in standard Planar coordinate system

   • Points are represented by coordinates P(X, Y)
   • Lines are represented by two points, marking their beginning and ending: L(P1(X1,Y1), P2(X2,Y2))
   • Calculate the distance between two points
   • Check if three segment lines can form a triangle

2. Write a function that removes all elements with a given value

   var arr = [1, 2, 1, 4, 1, 3, 4, 1, 111, 3, 2, 1, "1"];
   arr.remove(1); // arr = [2, 4, 3, 4, 111, 3, 2, "1"];

   • Attach it to the array object
   • Read about prototype and how to attach methods

3. Write a function that makes a deep copy of an object. The function should work for both primitive and reference types.

4. Write a function that checks if a given object contains a given property

   var obj  = ...;
   var hasProp = hasProperty(obj, "length");

5. Write a function that finds the youngest person in a given array of persons and prints his/hers full name

   • Each person has properties firstName, lastName and age, as shown:

   var persons = [
     { firstName : "Gosho", lastName: "Petrov", age: 32 },
     { firstName : "Bay", lastName: "Ivan", age: 81 }
     ...
   ];

6. Write a function that groups an array of persons by age, first or last name. The function must return an associative array, with keys - the groups, and values -arrays with persons in this groups. Use function overloading (i.e. just one function).

   var persons = { ... };
   var groupedByFirstName = group(persons, "firstname");
   var groupedByAge = group(persons, "age");