// ## ARRAYS ## //
console.log ("##ARRAYS##");
console.log ("==============");
// logEach //
console.log ("logEach");
console.log ("==============");
// Write a function logEach(array) that prints every element of the array and
// its index to the console . Example:

// > logEach(["Anthony", "John", "Carson"]);
// 0: Anthony
// 1: John
// 2: Carson

var logEach = function (array) {
  for ( var i = 0; i < array.length; i += 1 ) {

      console.log( i + ":" + array[i]);
  }
}
console.log (["Anthony", "John", "Carson"]);
logEach(["Anthony", "John", "Carson"]);

console.log ("==============");

// maxValue

console.log ("maxValue");
console.log ("==============");

//Write a function maxValue(array) that returns the largest value in the array.
//Assume array is an array of numbers.

// > maxValue([12, 6, 43, 2])
// 43

// > maxValue([])
// null

// > maxValue([-4, -10, 0.43])
// 0.43


var maxValue = function (array) {
  var biggestNumber = null;

  for ( var i = 1; i < array.length; i += 1 ) {
    var currentNumber = array[i];

// QUESTION 1
// why "largest === numb" in the if statemnt necessary as per the solution?)

    if ( biggestNumber < currentNumber ) {
      biggestNumber = currentNumber
    }
  }

  // QUESTION 2
  // soultion says to use return instead of console.log, why?
  console.log(biggestNumber);
}

// var result = maxValue([12, 6, 43, 2]);
// console.log(result);

console.log("Q1: [12, 6, 43, 2]")
maxValue([12, 6, 43, 2]);
console.log("Q2: []");
maxValue([]);
console.log("Q3: [-4, -10, 0.43]");
maxValue([-4, -10, 0.43]);


console.log ("==============");


// printRange

console.log ("printRange");
console.log ("==============");


// Write a function printRange(start, end) that prints all the numbers from
// start to end. If a range doesn't exist (start > end), then print "Bad Range" instead. Example:

// > printRange(22, 24)
// 22
// 23
// 24

// > printRange(5, 1)
// Bad Range

var printRange = function (start, end) {
  if(start > end) {
    console.log("Bad Range");
  }

// QUESTION 3
// Solution says else is not necessary, why?

  else {
    for (var i = start; i <= end; i += 1) {
      console.log(i)
    }
  }
}

console.log("Q1: (22, 24)");
printRange(22, 24);
console.log("Q2: (5, 1)");
printRange(5, 1);
console.log ("==============");


// ## FUNCTIONS ## //

console.log ("##FUNCTIONS##");
console.log ("==============");

// isPrime //

console.log ("isPrime");
console.log ("==============");

// Write a function isPrime(number) that returns a boolean indicating if
// number is prime or not. Assume number is a positive integer.

// > isPrime(2)
// true

// >isPrime(1693)
// true

// > isPrime(15)
// false

// > isPrime(303212)
// false

var isPrime = function(number) {
  if (number < 2) {
    return false
  }

//QUESTION 5
// why is else not necessary?

  else {
    for (var i = 2; i < number; i += 1){
      if (number % i === 0) {
        return false
      }
    }
  }
  return true
}

//QUESTION 4
//Is there a way to incorporate console.log into the function?
//so that it will log the result when we run it?

console.log("Q1: isPrime(2)");
console.log(isPrime(2));
console.log("Q2: isPrime(1693)");
console.log(isPrime(1693))
console.log("Q3: isPrime(15)");;
console.log(isPrime(15));
console.log("Q4: isPrime(303212)");
console.log(isPrime(303212));

console.log ("==============");




// firstNPrimes //

console.log ("firstNPrimes");
console.log ("==============");

// Using isPrime, write a function firstNPrimes(n) that returns an array
// of the first n prime numbers.

// > firstNPrimes(0)
// []

// > firstNPrimes(1)
// [2]

// > firstNPrimes(4)
// [2, 3, 5, 7]


var firstNPrimes = function(n) {
  var primes = [];
  var number = 2;


  // QUESTION 6
  // Is there a way to write this using For loop?

  // for (var i = n; i > primes.length; i += 1){
  //   if (isPrime(i)) {
  //     primes.push(i);
  //   }
  // }

  while (primes.length < n) {
    if (isPrime(number)) {
      primes.push(number);
    }

    number += 1;
  }

  // QUESTION 7
  // solution uses return why can't we use console.log instead?
  console.log(primes);
}

console.log("Q1: firstNPrimes(0)");
firstNPrimes(0);
console.log("Q2: firstNPrimes(1)");
firstNPrimes(1);
console.log("Q3: firstNPrimes(4)");
firstNPrimes(4);

console.log ("==============");

// // primesUpToN //
//
// console.log ("primesUpToN");
// console.log ("==============");
//
// function primesUpToN(n) {
//   var primeArr = [];
//
//   for (var i = 2; i <= n; i++) {
//     if (isPrime(i)) {
//       primeArr.push(i);
//     }
//   }
//   console.log(primeArr);
// }
//
// primesUpToN(4);


// sumOfNPrimes //

console.log ("sumOfNPrimes");
console.log ("==============");

// Using firstNPrimes, write a function sumOfNPrimes(n) that returns
// the sum of the first n prime numbers.

// > sumOfNPrimes(0)
// 0

// > sumOfNPrimes(1)
// 2

// > sumOfNPrimes(4)
// 17


var sumOfNPrimes = function(n) {
  var sum = 0;
  var primesArr = firstNPrimes(n);

  for(var i = 0; i < primesArr.length; i += 1) {
    sum += primesArr[i];
  }

  console.log(sum);
}

console.log("Q1: sumOfNPrimes(0)");
sumOfNPrimes(0);
console.log("Q2: sumOfNPrimes(1)");
sumOfNPrimes(1);
console.log("Q3: sumOfNPrimes(4)");
sumOfNPrimes(4);