Ruby conditionals return values. That is, a Ruby conditional such as if or case is an expression that returns a value.
You can use these values to simplify your code.
The examples below use the Interactive Ruby Shell, irb.
If-Else
Assume that these are defined:
def some_condition; true; end
def an_expression_that_returns_a_value; 0; end
def another_expression_that_returns_a_value; 1; end
This:
if some_condition
q = an_expression_that_returns_a_value
else
q = another_expression_that_returns_a_value
end
# => 0
q
# => 0
Can use the return value to become this:
q = if some_condition
an_expression_that_returns_a_value
else
another_expression_that_returns_a_value
end
# => 0
q
# => 0
Of course in this case the ternary operator would suffice, but it can be harder to read:
q = some_condition ?
an_expression_that_returns_a_value :
another_expression_that_returns_a_value
# => 0
q
# => 0
If-Elsif-Else
Now assume further that these are also defined:
def some_other_condition; false; end
def yet_another_expression_that_returns_a_value; 2; end
This:
if some_condition
q = an_expression_that_returns_a_value
elsif some_other_condition
q = another_expression_that_returns_a_value
else
q = yet_another_expression_that_returns_a_value
end
# => 0
q
# => 0
Can use the return value to become this:
q = if some_condition
an_expression_that_returns_a_value
elsif some_other_condition
another_expression_that_returns_a_value
else
yet_another_expression_that_returns_a_value
end
# => 0
q
# => 0
Case
This:
case
when some_condition
q = an_expression_that_returns_a_value
when some_other_condition
q = another_expression_that_returns_a_value
else
q = yet_another_expression_that_returns_a_value
end
# => 0
q
# => 0
Can use the return value to become this:
q = case
when some_condition
an_expression_that_returns_a_value
when some_other_condition
another_expression_that_returns_a_value
else
yet_another_expression_that_returns_a_value
end
# => 0
q
# => 0
Top comments (1)
Very interesting... Thanks. I will spent some time figuring this out...