Lambdas

Declare a lambda

l = lambda { puts "Hello World" }
# shorthand
l = -> { puts "Hello World" }
# transfer lambda
l.call
# output => Hello World

There are multiple ways to call a lambda

l.()
l[]

strict arguments

l = -> (count) { "Hello World " * count }
l.call 5
# output
# "Hello World Hello World Hello World Hello World Hello World "
l.call 5, 2
# output
wrong number of arguments (given 2, expected 1)

declare a lambda in block

def give_me_data
    puts "I am inside give_me_data method"
    l = -> { return 10 }
    l.call
    puts "I am back in give_me_data method"
end

return_value = give_me_data
puts return_value

# output
# I am inside give_me_data method
# I am back in give_me_data method
# nil # because puts return nil

lambdas are returned from the lambda itself, just like regular methods

l = -> { return 10 }
l.call

# output => 10

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