For loop (rarely used in Ruby) - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the basic syntax of a for loop in Ruby?

The for loop syntax in Ruby is: <br>

for variable in collection
  # code to execute
end

<br>It runs the code for each item in the collection.

beginner

Why is the for loop rarely used in Ruby?

Ruby prefers using iterators like .each because they are more flexible and fit Ruby's style better. For loops are less common and seen as less 'Ruby-like'.

intermediate

How does a for loop differ from an each iterator in Ruby?

A for loop uses an explicit loop variable and a collection, while .each passes each element to a block. <br>For loops do not create a new scope for the loop variable, but .each does.

beginner

Write a for loop in Ruby that prints numbers 1 to 3.

for i in 1..3
  puts i
end

<br>This prints:<br>1<br>2<br>3

intermediate

What happens to the loop variable after a for loop ends in Ruby?

The loop variable remains accessible after the for loop ends because for loops do not create a new scope for the variable.

Which of these is the correct way to write a for loop in Ruby?

A for (i = 1; i <= 5; i++) { puts i }

B for i in 1..5 puts i end

C for i = 1 to 5 do puts i end

D for i in range(1,5): puts i

Ruby uses 'for variable in collection' syntax. Option B matches this.

Why might Ruby programmers prefer .each over for loops?

A For loops are the only way to loop in Ruby

B For loops are faster

C <code>.each</code> creates a new scope for variables and fits Ruby style better

D <code>.each</code> cannot iterate over collections

.each is preferred because it creates a new scope and is more idiomatic Ruby.

What will this code print?<br>

for x in ["a", "b", "c"]
  puts x
end
puts x

A a b c and then 'c'

B a b c and then error

C Only a b c

D Error at the for loop

The variable x remains accessible after the loop with the last value 'c'.

Which statement about for loops in Ruby is TRUE?

A For loops iterate over collections using 'in'

B For loops create a new variable scope

C For loops are the most common looping method in Ruby

D For loops cannot iterate over ranges

For loops use 'for variable in collection' syntax to iterate.

What is a range in Ruby used for in a for loop?

A To stop the loop early

B To define a function

C To create a hash

D To specify a sequence of values to loop over

Ranges like 1..3 specify values from 1 to 3 to loop through.

Explain how a for loop works in Ruby and why it is less commonly used than other loops.

Think about how Ruby prefers blocks and iterators.

Write a simple Ruby for loop that prints each element of an array and describe what happens to the loop variable after the loop.

Remember that the loop variable stays accessible after the loop.