Integer class
/
when dividing only returns the whole
%
returns the remainder
Rubyists tend to end method names with a question marks when methods return true
or false
.
rand
returns a random number. rand(n)
will return a random integer between 0 and n-1 rather than 1 and n
object#method
is different from object.method
.to_f
is useful in converting an integer to a float.
Float class
Division with floats works the way we're used to. It returns fractional results, as a float
.
If either number when dividing with \
is a float, float division will be performed.
rand
can also be called without methods.
push == <<
for shorthand.
Array class
.at
method in an array refers to the index, which starts at 0. nil
represents absence of in index in the array aka doesn't exist.
In an array, to count backwards through a list of items, start with -1 (aka the last item)
.at == object[index]
shorthand.
.index
method returns the index where it resides
.split
will return an array of substrings
.split
with an argument tells the program to split at the character of the argument.
.split
ing with an empty argument ("")
turns a string into an array of individual characters.
.count
counts how many items are in a list if called with no arguments. If an argument is provided it counts how many times that argument occurs in the list.
.sample
returns an unpredicted item from an array
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