Which of the following is the correct syntax to sum all elements in an array arr using inject?

easy📝 Syntax Q12 of 15

Ruby - Enumerable and Collection Processing

Which of the following is the correct syntax to sum all elements in an array arr using inject?

Aarr.inject { |sum, n| sum / n }

Barr.inject(0) { |sum, n| sum + n }

Carr.inject(1) { |sum, n| sum * n }

Darr.inject { |sum, n| sum - n }

Step-by-Step Solution

Solution:

Step 1: Identify the correct initial value and operation
To sum elements, start with 0 and add each element: inject(0) { |sum, n| sum + n }.
Step 2: Check other options
arr.inject { |sum, n| sum - n } subtracts, C multiplies starting at 1, A divides. Only D sums correctly.
Final Answer:
arr.inject(0) { |sum, n| sum + n } -> Option B
Quick Check:
Sum with inject = D [OK]

Quick Trick: Sum needs 0 start and + inside block [OK]

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