[Solved] Find the mistake in this code: str = "abc123" str.gsub(/\d+/, '#') puts str — Ans: gsub does not modify str in place, so str remains unchanged | Ruby

Ruby - Regular Expressions

Find the mistake in this code:

str = "abc123"
str.gsub(/\d+/, '#')
puts str

AReplacement string must be double quotes, not single quotes

Bgsub does not modify str in place, so str remains unchanged

CRegex pattern is incorrect, should be /\d*/

Dputs cannot print the result of gsub

Step-by-Step Solution

Solution:

Step 1: Understand gsub behavior
gsub returns a new string and does not change the original string unless gsub! is used.
Step 2: Check code output
Since str is unchanged, puts str prints the original string.
Final Answer:
gsub does not modify str in place, so str remains unchanged -> Option B
Quick Check:
gsub returns new string, original unchanged unless gsub! used [OK]

Quick Trick: Use gsub! to modify string in place [OK]

Common Mistakes:

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