Javascript Assesement 1

assesment_1_Javascript.js

// David Ladowitz
// start time: 8:00pm


// Exercise 1....................................................
var newConcat = function(first, last){
  return (first + last)
};

newConcat('david', 'ladowitz')



// Exercise 2....................................................

var sum = function(array){
  var results = 0;
  for(i in array){
    results = results + array[i];
  }
  return results;
};




// Exercise 3....................................................

["javascript", "is", "a", "nice", "programming", "language", "as", "well"]

// What value is stored at index 3? -- 'nice'
// What is the index of the word "javascript?"  -- 0
// What is the length of the array?  -- 8


// Exercise 4....................................................



String.prototype.funString = function(){
  var results = [];
  for(i in this){
      if(i % 2 === 1){
        results.push(this.charAt(i).toUpperCase());
      }
      else{
        results.push(this.charAt(i));
      }
  }
  return results.reverse().join('');
};


// Exercise 5....................................................

var fizzblam = function(){
  for(var i = 1; i < 101 ; i++){
      if(i % 7 === 0 && i % 5 === 0){
        console.log("FizzBlam");
      }
      else if(i % 5 === 0){
        console.log("Fizz");
      }
      else if(i % 7 === 0){
        console.log("Blam");
      }
      else{
        console.log(i);
      }
  }

};


// Exercise 6....................................................

var GuessingGame = function(answer){
    return {
        guess: function(guess){
            if(guess === answer){
              this.solved = true;
              return "correct"
            }
            else if(guess < answer){
              return "low"
            }
            else{
              return "hi"
            }

        },
        solved: false

    }

};

// Usage printout from console:
//
// game1 = GuessingGame(10)
// Object
// game1.solved
// false
// game1.guess(5)
// "low"
// game1.guess(15)
// "hi"
// game1.guess(10)
// "correct"
// game1.solved
// true


// Exercise 7....................................................

// var myVariable = 'value'
    // Here we are setting myVariable to be a local variable with the value of 'value'.
    // It uses var to make it a local variable and not a global variable.

// this.myVariable = 'value'
    // I'm not entirely sure what is happening here. Generally 'this' can be used like 'self' in ruby.
    //


// Exercise 8....................................................

// Example 1: This iterates through each integer in the array, multiplies the integer by 100
// and prints it to the console. The original array is unchanged.

// Example 2: This iterates through each integer in the array, and returns the largest integer in the array
// It does this by assigning the first integer in the array to 'foo', then compares the next integer to 'foo'.
// If this integer is larger it will assign it to foo and continue for all integers. The original array is unchanged.

// Example 3: This returns the an array with the original integers increased by 80. It does this by iterating through
// each integer, adding 80 to it, then pushing the increased number to a new array. When its done it returns this
// new array. The original array is unchanged.

// Example 4: This returns an array of only the even numbers from the given array. It does this by iterating through
// the original array and tests the result of the interger % 2. All even numbers evaluate to 0. The even numbers are
// then put into a new array. The new array is returned. The original array is unchanged.

// Exercise 9....................................................

// fruits().peaches;
// -- 7

// fruits().peaches();
// -- Error
// 'peaches' is being called as a function with (). It is only a property though.

// fruits().apples;
// -- Undefined
// 'apples' is defined as a local variable in the function. It is not available outside the function.

// oranges;
// -- Error
// 'oranges' is being called as if it was it's own variable or function. It is only defined as a local variable inside of the fruits function.
//  Even if it was called properly it still wouldn't be available outside the fruits function.

// fruits().crate();
// -- 10

// Exercise 10....................................................

// console.log(animals.dog);
// -- 'woof'
// This is called properly

// console.log(animals.stepOnTail);
// -- meowZERS!!
// This should returns cat +"ZERS!!". cat is already defined as "meow", so the result is 'meowZERS!!'

// console.log(animals.cat);
// -- undefined
// This is because cat is not a property of animals, but is being called as if it was a properly of animals.
// Calling cat on it's own, would return 'meow'


// console.log(animals.duck);
// -- function () {
//     return 'quack';
//   }
// This is because we are calling the properly of duck, which happens to be a function. We didn't include
// (), which would call the function associated with duck,

// console.log(animals.duck());
// -- quack
// Here we call the function associated with duck, which retuns 'quack'.

// Exercise 11....................................................
// Return:
// This gives back a result to whatever may have called the function that is now giving the result. Generally
// this is a function or method and used by the computer, not a human. In Javascript you must explicity declare "return" if you want a function to
// return something. This is different than ruby, which returns the the last evaluated line of code.

// In the example below foo is returned to whatever called functionTwo. Without the 'return' keyword nothing would
// cbe given back.

// var functionTwo = function(array) {
//   var foo = array[0];
//
//   for (var i in array) {
//     if (array[i] > foo) {
//       foo = array[i];
//     }
//   }
//   return foo;
// };

// Console.log:
// This prints the results out to the Javascript console. Generally this console is part of a web browser.
// It is similir to ruby's 'print' or 'puts' functions. It will not give the results back to any other function.
// It is generally for human usage.
//
// In the example below a bunch of integers are printed on the console(screen) for humans to view.

// var functionOne = function(array) {
//      for (var i in array) {
//        console.log(array[i] * 100);
//      }
// };

// Exercise 12....................................................

// I had to look up the equivalet of Time.now in JS. It's 'new Date()'.
// fibSlow(35) took around 300 miliseconds, it seemed to change on different runs.
// fibFast(35) took around 1 miliseconds, it seemed to change on different runs.

//fibSlow takes so much longer because it uses recursion. For each number over 1 it needs to run the entire
// function all over again. Each run takes time.
// fibFast does not use recursion and only uses a loop. The loop is much faster than running the enitre function
// multiple times.



var fibSlow = function(n) {
 if (n === 0) {
   return 0;
 } else if (n === 1) {
   return 1;
 } else {
   return fibSlow(n-1) + fibSlow(n-2);
 }
};
var time1 = new Date();
fibSlow(35)
var time2 = new Date();
console.log(time2 - time1);



var fibFast = function(n) {
 var time3 = new Date();
 console.log(time3);
 fib = [0,1];

 for (var i = 2; i <= n; i++) {
   var last = fib[1];
   var fibN = fib[1] + fib[0];
   var fib = [last, fibN];
 }

  console.log(fib[1]);
var time4 = new Date();
console.log(time3);
console.log(time4 - time3);
};


// Last Question....................................................
// end time: 9:54pm
// This test took just under 2 hrs.