GATE CS 2026 Set 1 — Question 27

MSQ+1 / -0MediumLexical AnalysisCompiler DesignSyntax AnalysisSemantic AnalysisC ProgrammingProgramming & Data Structures

Compiler Design → C Programming

Last updated 5 September 2026

Question

Consider the following C statements: Which of the following options is/are correct?

Correct answer (C) S1 has a lexical error and S3 has a semantic error Solution Step-by-step analysis of the statements: 1. Statement S1: char *str1 = "Hello; /* Statement S1 */ contains an unterminated string literal. The opening double quote is not matched by a closing double quote on the same line. In compiler design, an unterminated string literal is a failure to form a valid token, which is categorized as a lexical error . 2. Statement S2: char *str2 = "Hello;"; /* Statement S2 */ is a valid C statement. It correctly declares a character pointer and initializes it with a properly terminated string literal. 3. Statement S3: int *str3 = "Hello"; /* Statement S3 */ is syntactically correct as it follows the grammar for variable declaration and initialization. However, it attempts to assign a value of type char * (the decayed type of the string literal) to a variable of type int * . This type mismatch is a violation of the language's type rules, which is caught during the semantic analysis phase. Thus, it is a semantic error . Conclusion: S1 has a lexical error. S2 is correct. S3 has a semantic error. This matches option (C). Turn this into a strength. Explore AI-powered practice and doubt support with Success Tracker.

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Correct answer (C) S1 has a lexical error and S3 has a semantic error Solution Step-by-step analysis of the statements: 1. Statement S1: char *str1 = "Hello; /* Statement S1 */ contains an unterminated string literal. The opening double quote is not matched by a closing double quote on the same line. In compiler design, an unterminated string literal is a failure to form a valid token, which is categorized as a lexical error . 2. Statement S2: char *str2 = "Hello;"; /* Statement S2 */ is a valid C statement. It correctly declares a character pointer and initializes it with a properly terminated string literal. 3. Statement S3: int *str3 = "Hello"; /* Statement S3 */ is syntactically correct as it follows the grammar for variable declaration and initialization. However, it attempts to assign a value of type char * (the decayed type of the string literal) to a variable of type int * . This type mismatch is a violation of the language's type rules, which is caught during the semantic analysis phase. Thus, it is a semantic error . Conclusion: S1 has a lexical error. S2 is correct. S3 has a semantic error. This matches option (C).

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