ACtE04 · Chapter 4Computer Organization & Embedded Systems🏛️ Past Licensure QuestionID: 4f7e9058
What is the output of a C program that attempts to modify a string literal?
What is the output of a C program that attempts to modify a string literal?
Multiple Choice Options
- A✓ Correct Option
Compile time error
- B
Hello World! 34
- C
Hello World! 10000
- D
Hello World! followed by a junk value
Detailed Technical Solution & Explanation
In C, string literals (e.g., "Hello World!") are stored in read-only memory segments. Attempting to modify a string literal (e.g., char *str = "Hello"; str[0] = 'h';) results in undefined behavior. Depending on the compiler and its settings, this typically manifests as a compile-time error (with strict type checking) or a runtime segmentation fault.
Given the options, the expected answer is a compile-time error, which occurs when the compiler detects an attempt to write to a const-qualified or read-only string literal.
Option Analysis:
•
Option A (Compile time error): ✅ Correct. The compiler detects the invalid modification attempt and reports an error.
•
Option B (Hello World! 34): Would require successful string manipulation and arithmetic output, which won't occur.
•
Option C (Hello World! 10000): Would require successful execution, which won't occur.
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Option D (Hello World! followed by a junk value): Would require partial execution, which won't occur if compilation fails.
Reference: Mock Test 06NEC Licensure Syllabus