Ruby redo and retry Statement

In Ruby, Redo statement is used to repeat the current iteration of the loop. redo always used inside the loop. The redo statement restarts the loop without evaluating the condition again.

# Ruby program of using redo statement

#!/usr/bin/ruby
restart = false

# Using for loop
for x in 2..20
    if x == 15
        if restart == false

            # Printing values
            puts "Re-doing when x = " + x.to_s
            restart = true

            # Using Redo Statement
            redo
        end
    end
    puts x
end

Output:

2
3
4
5
6
7
8
9
10
11
12
13
14
Re-doing when x = 15
15
16
17
18
19
20

In above example, redo statement apply when x = 15.

retry Statement:

To repeat the whole loop iteration from the start the retry statement is used. retry always used inside the loop.

Example #1:

# Ruby program of retry statement

# Using do loop
10.times do |i|
  begin
    puts "Iteration #{i}"
    raise if i > 2
  rescue

    # Using retry
    retry
  end
end

Output:

Iteration 0
Iteration 1
Iteration 2
Iteration 3
Iteration 3
Iteration 3
...

Example #2:

# Ruby program of retry statement
def geeks
  attempt_again = true
  p 'checking'
  begin

    # This is the point where the control flow jumps
    p 'crash'
    raise 'foo'
      rescue Exception => e
        if attempt_again
          attempt_again = false

      # Using retry
      retry
    end
  end
end