[Solved] The following Ruby code prints nothing. What is the problem?text = "HELLO" puts text.upcase! — Ans: The method upcase! returns nil if no changes made | Ruby

Ruby - Basics and Runtime

The following Ruby code prints nothing. What is the problem?

text = "HELLO"
puts text.upcase!

AMissing parentheses for method call

BUsing <code>upcase!</code> on a string literal causes error

CThe method <code>upcase!</code> returns nil if no changes made

DStrings are not objects, so methods can't be called

Step-by-Step Solution

Solution:

Step 1: Understand upcase! behavior
The upcase! method modifies the string in place and returns nil if no changes were made.
Step 2: Analyze the code's output
Since "HELLO" is uppercase, upcase! makes no changes and returns nil, so puts prints nothing.
Step 3: Identify the error cause
The return value nil is printed when no mutation occurs.
Final Answer:
upcase! returns nil if no changes made -> Option C
Quick Check:
Bang methods can return nil if no change [OK]

Quick Trick: Bang (!) methods may return nil if no change happens [OK]

Common Mistakes:

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