```
def prime(n)
puts "That's not an integer." unless n.is_a? Integer
is_prime = true
for i in 2..n-1
if n % i == 0
is_prime = false
end
end
```

I DON'T UNDERSTAND WHAT "FOR I IN 2..N-1" WHICH IS LINE 4 OF ABOVE CODE

```
def prime(n)
puts "That's not an integer." unless n.is_a? Integer
is_prime = true
for i in 2..n-1
if n % i == 0
is_prime = false
end
end
```

I DON'T UNDERSTAND WHAT "FOR I IN 2..N-1" WHICH IS LINE 4 OF ABOVE CODE

`for i in 2..n-1`

describes iteration over a range from 2 to 1 less than `n`

.

Compare this to Python:

`for i in range(2, n-1):`

or JavaScript:

`for (var i = 2; i < n; i++){}`