LANGUAGE » RUBY

Control flow

Last updated:
Reference:docs.ruby-lang.org

Condition ​

ruby
if cond1
  do_something
elsif cond2
  do_something
else
  do_something
end

unless cond1
  do_something
else
  do_something
end

do_something if cond
do_something unless cond

cond ? was_true : was_false

Loop ​

ruby
loop do
  next if cond  # Same as continue, skip this iteration
  do_something
  break if cond
end

For loop ​

ruby
## Include last number
for num in 1..10
  puts num
end

## Exclude last number
for num in 1...10
  puts num
end

While loop ​

ruby
while cond
  do_something
end

until cond
  do_something
end

Do while loop ​

do + end is the same as { + }.

ruby
95.upto(100) do |num|
  puts num
end

95.downto(90) do |num|
  puts num
end

my_array.each do |item|
  do_something
end

10.times do
  do_something
end

Switch ​

ruby
case my_var
  when 0
    do_something
  when 1
    do_something
  else
    do_something
end