Checking if a variable is an integer

In case you don't need to convert zero values, I find the methods `to_i` and `to_f` to be extremely useful since they will convert the string to either a zero value (if not convertible or zero) or the actual `Integer` or `Float` value.

"0014.56".to_i # => 14
"0014.56".to_f # => 14.56
"0.0".to_f # => 0.0
"not_an_int".to_f # 0
"not_a_float".to_f # 0.0

"0014.56".to_f ? "I'm a float" : "I'm not a float or the 0.0 float"
# => I'm a float
"not a float" ? "I'm a float" : "I'm not a float or the 0.0 float"
# => "I'm not a float or the 0.0 float"

EDIT2 : be careful, the `0` integer value is not falsey it's truthy (`!!0 #=> true`) (thanks @prettycoder)

EDIT

Ah just found out about the dark cases... seems to only happen if the number is in first position though

"12blah".to_i => 12

You can use the `is_a?` method

>> 1.is_a? Integer
=> true
>> "[email protected]".is_a? Integer
=> false
>> nil.is_a? Integer
=> false

Basically, an integer **n** is a power of three, if there exists an integer **x** such that **n == 3x**.

So to verify that you can use this functions
```
def is_power_of_three(n)
return false unless n.positive?

n == 3**(Math.log10(n)/Math.log10(3)).to_f.round(2)
end
```