Object Drills 2

ObjDrill2_enrollInSummerSchool.js

// Write a function called enrollInSummerSchool that takes a single argument, students. 
// students is an array of objects, with each object representing a student — 
// for example, {name: 'Tim', status: 'Current student', course: 'Biology'}.

// enrollInSummerSchool should return an array of objects. 
// For each object from the original array, it should return the original name and course, 
// but should update the status to In Summer school. 

function enrollInSummerSchool(students) {
  var results = [];
  for (var i=0; i<students.length; i++) {
    var student = students[i];
    results.push({
     name: students[i].name,
     status: 'In Summer school',
     course: students[i].course
   });
  }
   return results;
}

ObjDrill2_findById.js

// Write a function called findById. This function takes two arguments 'items' and 'idNum'. 
// 'items' is an array of objects. idNum is the id we're trying to find in items.

// Calling findById([{id: 1, foo: 'bar'}, {id: 2, foo: 'bizz'}], 2) should return {id: 2, foo: 'bizz'}.


function findById(items, idNum) {
  for (var i=0; i<items.length; i++) {
      if (idNum === items[i].id) {
      return items[i];
      }
  }
}

ObjDrill2_makeStudentReports.js

// Make Student Reports

// Write a function called 'makeStudentReports' that takes a single argument 'data' ('data' is an array of objects).
// Each object in the array represents a student and their letter grade for each example {name:'John', grade: 'A'}
// makeStudentReports should return an array of strings for each item in data return a string that looks like:
// '[name]:[grade]' - the name and grade values should be substituted in.

function makeStudentsReport(data) {
  var results = [];
  for (var i=0; i<data.length; i++) {
    var item = data[i];
    results.push(item.name + ': ' + item.grade);
  } 
  return results;
}                

// Solution using .map method
// below produces the same result as ^^, but with `.map`
function makeStudentsReportAlt(data) {
  return data.map(function(d) {
    return d.name + ': ' + d.grade;
  });
}
// *** HOW DOES THE FUNCTION KNOW THAT d = the item on the array?

ObjDrill2_toDoListFactory.js

// Write a function called 'makeToDos'. This function should take two arguments: 'owner' and 'toDos'. 
// 'owner' is a string of the name of the owner of the to do list. 
// 'toDos' is an array of strings representing items to be done.
// 'makeToDos' should return an object with 'owner' and 'toDos' properties that correspond to the values passed in as arguments.

// It should also have a method called .generateHtml. This method should return a string representing an unordered list. 
// Each item from toDos should appear as an <li> in the list. 

// For example: if 'makeToDos' was called like this: 
//       makeToDos('Teddy', ['wake', 'eat', 'drink', 'work', 'sleep']),

// calling .generateHtml on the resulting object should generate a string like this: 
//      '<ul><li>wake</li><li>eat</li><li>drink</li><li>work</li><li>sleep</li></ul>'.


// Couldn't figure out how to do it


// Curriculum solution:

// owner - string meaning the name of the owner
// toDos - ARRAY of STRINGS representing ITEMS to be done
// makeToDos - should RETURN an OBJECT with 'owner' and 'toDos' properties that
//             correspond to values passed as arguments

// Should have a method called '.generateHtml' which should return a string
// representing an UNORDERED LIST, each ITEM from 'toDos' should appear as a <li>
// in the list

function makeToDos(owner, toDos) {
   return {
     owner: owner,
     toDos: toDos,
     generateHtml: function() {
       var html = '<ul>';
       this.toDos.forEach(function(todo) {
         html+= '<li>' + todo + '</li>';
       });
       return html + '</ul>';
     }
   }
}

ObjDrill2_validateKeys.js

// Write a function called validateKeys. This function takes two arguments, 'object' and 'expectedKeys'. 
// 'object' is an object that we want to valdiate keys for. 'expectedKeys' is an array of keys that we EXPECT TO FIND 
// on the object.

// validateKeys should return false if 'object' contains extra keys not in 'expectedKeys' or missing keys
// validateKeys should return false if 'object' contains different keys than in 'expectedKeys'
// ...therefore,
// validateKeys should return true if object has all of the keys from expectedKeys and no additional keys



// running the function with `objectA` and `expectedKeys`
// should return `true`
var objectA = {
  id: 2,
  name: 'Jane Doe',
  age: 34,
  city: 'Chicago'
}

// running the function with `objectA` and `expectedKeys`
// should return `false`
var objectB = {
  id: 3,
  age: 33,
  city: 'Peoria'
}

// ********** MY SOLUTION HERE *****************

// object = argument thats an object
// expectedKeys = argument thats an array of keys

var expectedKeys = [
  'id', 'name', 'age', 'city'
];

function validateKeys(object, expectedKeys) {  
    if (Object.keys(object).length !== expectedKeys.length) {
    return false;
  }
    for (var i=0; i<expectedKeys; i++) {
      if (Object.keys(object) !== expectedKeys[i]);     
      return false;
    }
  return true;
}

// For some reason I got it to work with 2nd argument in loop logic ' i<expectedKeys ' and doesn't
// work with ' i<expectedKeys.length ' so now Im more confused


// Remember to use logic operators: ! , !== , ===


// 1. First return the 'false' statements by disqualifying
//    if arg1.length !== arg2.length return false
//
// 2. Validate if keys in arg1 (the object) match keys (or items in array) in arg2 
//    keys in arg1 !== items in arg2 - return false
//   
//    a. for..in loop iterating expectedKeys
//    b. if arg1 content doesn't match arg2 content        
//
// 3. If non of the above then its true
//     return true;

// Curriculum Solution uses the .find() method

function validateKeys(object, expectedKeys) {
  if (Object.keys(object).length !== expectedKeys.length) {
    return false;
  }
  
  for (var i; i<expectedKeys.length; i++) {
    if (!Object.keys(object).find(function(key) {
      return key === expectedKeys[i];
      })) {
      return false;
    }
  }

  return true;
}