[Solved] Identify the error in this Ruby function intended to be pure:def increment(x) @count += 1 x + 1 end — Ans: Modifies an instance variable, causing side effects. | Ruby

Ruby - Functional Patterns in Ruby

Identify the error in this Ruby function intended to be pure:

def increment(x)
  @count += 1
  x + 1
end

ADoes not return a value.

BModifies an instance variable, causing side effects.

CUses incorrect syntax for addition.

DFunction name is invalid.

Step-by-Step Solution

Solution:

Step 1: Check for side effects
The function changes @count, an instance variable, which is a side effect.
Step 2: Confirm return value and syntax
Function returns x + 1 correctly and syntax is valid.
Final Answer:
Modifies an instance variable, causing side effects. -> Option B
Quick Check:
Side effects break purity = Modifies an instance variable, causing side effects. [OK]

Quick Trick: Changing instance variables breaks pure function rules [OK]

Common Mistakes:

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