CSE 3901 STUDY GUIDE 2026 EXAM MOST TESTED QUESTIONS AND VERIFIED SOLUTIONS

CSE 3901 STUDY GUIDE 2026 EXAM MOST TESTED
QUESTIONS AND VERIFIED SOLUTIONS

a working tree + store + index - ANSWER-github: what is a repository?

the project itself - ANSWER-github: what is a working tree?

hidden directory (.git) in root directory of working tree



User never accesses .git directly



Store records project development history - ANSWER-github: what is a store?

DAG of commits

Each commit represents a complete snapshot of the entire project - ANSWER-github: what is
history?

virtual snapshot stored in .git/index - ANSWER-github: what is an index?

a pointer to a commit - ANSWER-github: what is a branch?

git branch nameOfBranch - ANSWER-github: command to create a new branch

git checkout fix - ANSWER-github: change to branch titled 'fix'

git add --all .

git commit - ANSWER-github: add and commit changes to local store

http://web.cse.ohio-state.edu/~giles/3901/lectures/lecture02.pdf - ANSWER-github: problem
on slide 42 http://web.cse.ohio-state.edu/~giles/3901/lectures/lecture02.pdf

0, 1, 2, 3, 4 - ANSWER-ruby: what is the following range 0..4

0, 1, 2, 3 - ANSWER-ruby: what is the following range 0...4

Returns -1/0/1 if LHS is smaller/equal/larger than RHS - ANSWER-ruby: what does the <=>
operator do?

-1 - ANSWER-ruby: what does "cab" <=> "da" return?

1 - ANSWER-ruby: what does "cab" <=> "ba" return?

,i = 34, j = 35 - ANSWER-i = 34

j = i # i and j are aliases

j = j + 1 # does this increment i too?

what is the value of i and j?

prints 0 to 24 - ANSWER-what does the following statement do?

i = 10

25.times { | i | puts i }

"tania".length - ANSWER-ruby: write a statement that returns the length of your name

"exam".reverse - ANSWER-ruby: write a statement that reverses the word "exam"

puts "Tania".upcase - ANSWER-ruby: write a statement that prints "Tania" in uppercase

puts "Tania".downcase - ANSWER-ruby: write a statement that prints "Tania" in lowercase

puts "What is your first name?"

name = gets.chomp

puts "Your first name is #{name.capitalize!}" - ANSWER-ruby: write a statement that asks for the
users first name and prints the result in the following format: Your first name is (name). The
name should be capitalized

for i in 1..20

next if i % 2 != 0

puts i

end - ANSWER-ruby: write a for loop that prints all even numbers between 1 and 20

num = 1

until num > 10

puts num

num += 1

end - ANSWER-ruby: write a looping using until that prints numbers 1 to 20

Start of method

In the block

, In the block

End of method - ANSWER-What does the following code output?

def call_block

puts 'Start of method'

yield

yield

puts 'End of method'

end

call_block {puts 'In the block'}

equal? : Checks if the object id is the same (reference value)



eql? : True if the receiver and argument have both the same type and equal values (same hash
key).



=== : tests range inclusion



== : Checks if the value of two operands are equal or not - ANSWER-What's the difference
between equal?, eql?, ===, and == ?

10^20 - ANSWER-a = 10

b = 20

What is the return value for a**b?

position = "cat o' 9 tails" =~ /a/

puts position - ANSWER-write a statement that prints the index of the first occurrence of 'a' in
the string "cat o' 9 tails"

FixNum, Float, Rational, Complex - ANSWER-what are the different number types in ruby?

#=> expected - ANSWER-what is the ruby convention to indicate an expected result as a
comment on a line of code?