In response to issue #86159 + Jay's response:

"In the function for Chapter 4's Exercise #4, the first line of the function body, greatestNumberSoFar = array[0], is redundant.--Kelvin Wong

Jay Wengrow says: Thanks, Kelvin - can you please explain why it's redundant? The code throws an error if we remove that line."

The variable 'greatestNumberSoFar' isn't referenced anywhere else in the remainder of the function's body, and the function seems to behave as expected for simple test cases without that line:

def greatestNumber(array):

# remainder of the function's body

for i in array:

isIValTheGreatest = True

for j in array:

if j > i:

isIValTheGreatest = False

if isIValTheGreatest:

return i--Kelvin Wong

The Exercise Solution for Chapter 11, exercise 4 states:

"
Since we need to return the index at which we find the "x", we can use the trick of passing the index as an extra parameter:

def index_of_x(string, i=0)
return i if string[i] == "x" return index_of_x(string, i + 1)
end
"

Following the "Thinking process" outlined in this chapter, the solution I came to...or that came to me... was:

"
def i_of_x str
return str[0] == 'x' ? 0 : i_of_x(str[1, str.length]) + 1
end
"
We don't actually need an index tracker as this solution adds to the index with each recursive call. Perhaps it would be helpful to use or include this alternative?--Nathan Classen