You want to read a file and create a hash where keys are line numbers (starting at 1) and values are the lines without newline characters. Which code correctly does this?

hard📝 Application Q8 of 15

Ruby - File IO

AFile.readlines('file.txt').to_h { |line| [line, line.chomp] }

BFile.readlines('file.txt').each_with_index.to_h { |line, i| [i, line.strip] }

CHash[File.readlines('file.txt').map.with_index { |line, i| [i + 1, line.chomp] }]

DFile.readlines('file.txt').map { |line| [line.chomp, line] }.to_h

Step-by-Step Solution

Solution:

Step 1: Understand mapping lines to line numbers
Using map.with_index allows pairing each line with its index starting at 0.
Step 2: Adjust index and remove newline
Adding 1 to index for line numbers starting at 1, and using chomp removes newline.
Step 3: Convert array of pairs to hash
Hash[] converts array of key-value pairs into a hash.
Final Answer:
Hash[File.readlines('file.txt').map.with_index { |line, i| [i + 1, line.chomp] }] -> Option C
Quick Check:
Use map.with_index + chomp + Hash[] = D [OK]

Quick Trick: Use map.with_index and chomp to build line-numbered hash [OK]

Common Mistakes:

Using each_with_index.to_h incorrectly
Swapping keys and values in hash
Not removing newline characters

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You want to read a file and create a hash where keys are line numbers (starting at 1) and values are the lines without newline characters. Which code correctly does this?

Step 1: Understand mapping lines to line numbers

Step 2: Adjust index and remove newline

Step 3: Convert array of pairs to hash

Final Answer:

Quick Check:

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