Challenges

Write a multiply function that finds the product of two numbers.
```
multiply(5, 7) => 35
```
Write a function that takes in a number and returns true if the number is even and false if the number is odd (Hint: Look up the % operator).
```
isEven(4) => true
```
Write a function that swaps two values at two different indexes in an array.
```
swap(["moe", "larry", "curly"], 0, 2) => ["curly", "larry", "moe"]
```
Write a function that generates a random number in a specified range (Hint: Look up Math.random()).
```
getRand(5, 10) => 8 (any number between 5 and 10)
```
Write a function that generates an array of specified length that contains random numbers from 1 to 100.
```
randArr(3) => [23, 11, 82]
```

Stretch Challenges

Write a getMax function that finds the maximum number in an array.
Write a function called explainMather that takes in three arguments: two numbers and a function called mather. The explainMather function should pass the two numbers into mather and write out a message in the console to show the two number inputs and the output from mather. Test explainMather by passing in your multiply function from challenge #1.
Write a vowels function that counts the number of vowels in a given string.
merge(arr1, arr2)

Write a function that takes two sorted arrays of numbers and returns a merged array of the sorted numbers. For example, if the input arrays were var arr1 = [3,6,11] and var arr2 = [2,4,5,8,9], the returned array would be: [2,3,4,5,6,8,9,11].
letterCount(word)

Write a function that counts the number of times each letter occurs in a given string. It should return an object containing the count for each letter. For example, the string "apple" would return the following:
```
{
 a: 1,
 p: 2,
 l: 1,
 e: 1
}
```
Bonus: Make sure that lower case letters and upper case letters count for the same character. Also, ignore spaces and punctuation.
sillySum(arr)

Write a function that takes an array of numbers and returns the sum of each number multiplied by its index.
```
count += (number * index)
```
numSquare(max)

Create a function called numSquare that will return an array of all perfect square numbers up to, but not exceeding a max number.