Which of the following Ruby code snippets correctly defines a lambda that takes one argument and doubles it?

easy📝 Syntax Q3 of 15

Ruby - Blocks, Procs, and Lambdas

Adouble = lambda x { x * 2 }

Bdouble = Proc.new { |x| x * 2 }

Cdouble = ->(x) { x * 2 }

Ddouble = lambda ->(x) { x * 2 }

Step-by-Step Solution

Solution:

Step 1: Identify correct lambda syntax
In Ruby, a lambda can be created using the stabby lambda syntax: ->(args) { block }.
Step 2: Evaluate each option
double = ->(x) { x * 2 } uses the correct stabby lambda syntax.
double = Proc.new { |x| x * 2 } creates a Proc, not a lambda.
double = lambda x { x * 2 } is invalid syntax; lambda requires parentheses around arguments.
double = lambda ->(x) { x * 2 } incorrectly nests lambda and stabby lambda syntax.
Final Answer:
double = ->(x) { x * 2 } -> Option C
Quick Check:
Use ->(args) { } for lambdas [OK]

Quick Trick: Use ->(args) { } for lambdas [OK]

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