Language Tutorials/Ruby/If-Elsif-Else and Case Statements

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Most programming languages have some sort of if-else statement.^{[citation needed]}

If and If-Else Statements

In Scratch, an if-else statement is shown like so:

if <> then
else

In Ruby, one can write an if-else statement like this:

if
  # Code
else
  # Code
end

In both languages, one can insert something that returns either true or false after "if", and some code in the if-else statement, like so:

if <[1] = [2]> then
set [variable v] to [5]
else
set [variable v] to [6]
end

if 1 == 2
  variable = 5
else
  variable = 6
end

Also in both languages, one can shorten it to just an if statement if an else is not needed for that particular situation.

if <[1] = [2]> then
set [variable v] to [5]
end

if 1 == 2
  variable = 5
end

If-Elsif-Else Statements

In Ruby, there's an extra statement like this, called the "if-elsif-else" statement. It is shown like this:

if
  # Code
elsif
  # Code
else
  # Code
end

In the code above, if the condition after "if" is true, it will execute that code. If it's not, it will move onto the elsif. After "elsif", there is a condition. If that's true, it will do that code. If it's not, it will do the code in the else statement.

The equivelent for these statements in Scratch would be:

if <> then
else
if <> then
else
end

One can add more elsifs as needed, which would turn the statement into an if-elsif-elsif-etc.-else statement.

if 5 == 5
  # Code
elsif 4 == 2
  # Code
elsif 8 == 9
  # Code
elsif x > 3
  # Code
else
  # Code
end

Case Statements

There's another statement called the case statement. It is written in Ruby like this:

case
when
  # Code
when
  # Code
when
  # Code
else
  # Code
end

Here's a case statement with code and stuff in it:

case var
when 5
  var += 1
when 3
  puts "Hello, World!"
when 2
  print "No enter after me... :("
else
  puts "If neither 5, 3, nor 2 is equal to var, I will be executed!"
  var = 1000000
end