Which ONE of the following statements is FALSE regarding the symbol table? A) Symbol table is responsible for keeping track of the scope of variables. B) Symbol table can be implemented using a binary search tree. C) Symbol table is not required after the parsing phase. D) Symbol table is created during the lexical analysis phase.

Official answer: C) Symbol table is not required after the parsing phase.. Explanation: A symbol table is a central data structure maintained by the compiler to store information about identifiers (such as variable names, function names, types, scope, and memory offsets). - Option A is true: A symbol table is used to track the scope and visibility of identifiers (e.g., using block-structured symbol tables). - Option B is true: Symbol tables can be implemented using data structures like hash tables, binary search trees, linked lists, or linear lists. - Option C is false: The symbol table is essential throughout almost all phases of the compiler, including semantic analysis (for type and declaration checking), intermediate code generation, optimization, and target code generation (for memory allocation/offset calculation), as well as by debuggers. - Option D is true: Identifiers are recognized and initially entered into the symbol table during the lexical analysis phase. Hence, statement C is FALSE.

A) Symbol table is responsible for keeping track of the scope of variables.

B) Symbol table can be implemented using a binary search tree.

D) Symbol table is created during the lexical analysis phase.

Lexical Analysis

GATE CSE 2025 Set 1 · Q12

MCQ1 markEasy

Time00:00

Which ONE of the following statements is FALSE regarding the symbol table?

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Solution

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Official answer: C) Symbol table is not required after the parsing phase.

Lexical Analysis

A symbol table is a central data structure maintained by the compiler to store information about identifiers (such as variable names, function names, types, scope, and memory offsets).

Option A is true: A symbol table is used to track the scope and visibility of identifiers (e.g., using block-structured symbol tables).
Option B is true: Symbol tables can be implemented using data structures like hash tables, binary search trees, linked lists, or linear lists.
Option C is false: The symbol table is essential throughout almost all phases of the compiler, including semantic analysis (for type and declaration checking), intermediate code generation, optimization, and target code generation (for memory allocation/offset calculation), as well as by debuggers.
Option D is true: Identifiers are recognized and initially entered into the symbol table during the lexical analysis phase.

Hence, statement C is FALSE.

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This Lexical Analysis previous year question is Q12 of the GATE CSE 2025 Set 1 paper. Find more GATE CSE PYQs on Lexical Analysis in Compiler Design, or browse all GATE CSE PYQs.

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Lexical Analysis in GATE CSE

Lexical Analysis has 7 GATE CSE PYQs across 6 papers from 2011 to 2026. 5 of them are 1-mark MCQs like this one, and it is the only one in GATE CSE 2025 Set 1.

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Independent practice explanation verified by the GateAI team. GATE is conducted by the IITs; question text follows the official paper.