ex src HOF, exceptions, __proto__, return, bind, this and anonymous f…

paperproblems/array-functions/problem1.txt

@@ -13,4 +13,6 @@ var dogs = animals.filter(
                 function(animal)
                      {return animal.species === 'dog';});
 
-console.log(dogs.length);
+console.log(dogs.length);
+
+//2

paperproblems/array-functions/problem2.txt

@@ -13,4 +13,6 @@ var letterN = animals.filter(function(animal) {
     return animal.name !== undefined && animal.name[0] === 'N'
 });
 
-console.log(letterN[0].name);
+console.log(letterN[0].name);
+
+//Nacho

paperproblems/array-functions/problem3.txt

@@ -10,4 +10,6 @@ var animals = [
 var animalNames = animals.map(
                     function(animal) {return animal.name});
 
-console.log(animalNames.join());
+console.log(animalNames.join());
+
+//Nacho,Ramses,Flufftail,Popcorn,Neckbeard,

paperproblems/array-functions/problem4.txt

@@ -11,8 +11,8 @@ function isDog(animal) {
     return animal.species === 'dog';
 }
 
-animals.some(isDog)
-animals.every(isDog)
+animals.some(isDog) //true
+animals.every(isDog) //false
 
 
 

paperproblems/arrow-functions/problem1.txt

@@ -2,18 +2,18 @@ For each of the following expressions:
  - Does it have a syntax error?
  - If it doesn't have a syntax error, what are the probable input and output types of the function?
 
-a) x => x + 1
+a) x => x + 1  //no syntax error, input type: number, output type: number
 
-b) x, y => x * y
+b) x, y => x * y //need () for the arguments, input type: number, output type: number
 
-c) x => { x * 2 }
+c) x => { x * 2 } //need no {} OR a return before x*2, input type: number, output type: number
 
-d) (x, z) => {console.log(z); return x * z}
+d) (x, z) => {console.log(z); return x * z} //no syntax error, input type: number, output type: number
 
-e) x => console.log(z); return x * z
+e) x => console.log(z); return x * z //need {} andz must be defined, input type: number, output type: number
 
-f) (x) => x * 2
+f) (x) => x * 2 //ok but you remove () for the parameter, input type: number, output type: number
 
-e) () => console.log("hello")
+e) () => console.log("hello") //no syntax error, input type: none, output type: string
 
 When you're done, check all your answers in the developer console.

paperproblems/callbacks/problem1.txt

@@ -12,4 +12,6 @@ function h() {
     setTimeout(f, 1000);
 }
 
-setTimeout(h, 200);
+setTimeout(h, 200);
+
+//This programme log "Hello!" after 1700 ms

paperproblems/callbacks/problem2.txt

@@ -8,4 +8,9 @@ function h() {
     setInterval(g, 1000);
 }
 
-setInterval(h, 1000);
+setInterval(h, 1000);
+
+//This program calls h() every second
+//h() calls g() every second
+//g() logs "Hello!"
+//There is an "Hello!" more at each call

paperproblems/classes/problem1.txt

@@ -11,4 +11,4 @@ class Dog {
     }
 }
 
-var someDog = new Dog("schnitzel", 2, "male");
+var someDog = new Dog("schnitzel", 2, "male");

paperproblems/classes/problem2.txt

@@ -12,11 +12,15 @@ class Person {
     }
     toString() {
         return "My name is " + this.name +
-          "and I'm " + this.age + " and I make " + this.salary;
+          " and I'm " + this.age + " and I make " + this.salary;
     }
 }
 
 var bob = new Person(25, "Bob", 40000);
 
 bob.increaseSalary(-500);
-console.log(bob.toString());
+console.log(bob.toString());
+
+//output: 
+Yay!
+My name is Bob and I'm 25 and I make 39500

paperproblems/conditional-operator/problem1.txt

@@ -4,4 +4,6 @@ function f(x) {
     return x < 5 ? 3 : x > 8 ? 4 : x == 6 ? 12 : 9;
 }
 
-console.log(f(5));
+console.log(f(5));
+
+//output : 9

paperproblems/constructor-functions/problem2.txt

@@ -12,4 +12,6 @@ var bob = new Person("Bob", 30);
 
 Person.prototype.leave = function() {return this.name + " is leaving";}
 
-bob.leave();
+bob.leave();
+
+//output "Bob is leaving" because the property leave is correctly added to the prototype of the function Person

paperproblems/constructor-functions/problem3.txt

@@ -16,4 +16,6 @@ Person.prototype.salary = Person.prototype.salary + 300;
 Person.__proto__.salary = Person.__proto__.salary + 400;
 bob.salary = bob.salary + 50;
 
-console.log(bob.salary);
+console.log(bob.salary);
+
+// output : 40450 because line 16 needs a "prototype" instead of "__proto__" 

paperproblems/constructor-functions/problem4.txt

@@ -12,4 +12,6 @@ var bob = Person("Bob", 30);
 
 bob.name = bob.name + " Dole";
 
-bob.greet();
+bob.greet();
+
+//output: error because the var bob need to use the constructor to define all its properties : var bob = new Person("Bob", 30)

paperproblems/constructor-functions/problem5.txt

@@ -11,4 +11,13 @@ function Person(name, age) {
 }
 
 var bob = new Person("Bob", 30);
+
+
+function person(name, age) {
+    return {fname: name, age: age, greet: function(){console.log("Hello my name is " + name)}}
+}
+
+var bob = person('Bob', 30)
+
 var sue = new Person("Sue", 24);
+

paperproblems/inheritance/problem1.txt

@@ -24,4 +24,6 @@ class Square extends Shape {
 }
 
 var s = new Square(5);
-console.log(s.toString());
+console.log(s.toString());
+
+//output : square with area 25 and perimeter 20

paperproblems/inheritance/problem2.txt

@@ -11,3 +11,20 @@ class Shape {
           this.area() + " and perimeter " + this.perimeter();
     }
 }
+
+class Rectangle extends Shape {
+    constructor(height, width) {
+        super("rectangle");
+        this.height = height;
+        this.width = width;
+    }
+    area() {
+        return this.height * this.width;
+    }
+    perimeter() {
+        return this.height * 2 + this.width * 2;
+    }
+}
+
+var s = new Rectangle(5,3);
+console.log(s.toString());

paperproblems/variable-scoping/problem1.txt

@@ -9,3 +9,7 @@ function f() {
 
 f();
 f();
+
+//output:
+2
+4

paperproblems/variable-scoping/problem2.txt

@@ -7,4 +7,8 @@ function f() {
 }
 
 f();
-f();
+f();
+
+output:
+2
+2

paperproblems/variable-scoping/problem3.txt

@@ -11,4 +11,10 @@ function f() {
 
 f();
 f();
-console.log(y);
+console.log(y);
+
+//output:
+
+7
+9
+3

paperproblems/variable-scoping/problem4.txt

@@ -14,4 +14,6 @@ function f() {
         }
 
     }
-}
+}
+
+//variables in scope: f, y, g, z, h and p