Which data structure in a compiler is used for managing information about…

Answer: Symbol table — the symbol table is used to manage information about variables and their attributes.

• What the symbol table stores: identifier names, data types, scope level (where each identifier is visible), memory location or offset, and other attributes such as parameter lists, array sizes, and declaration position.

• Typical implementations: often implemented with hash tables for fast lookup; compilers also use a stack or nested tables to represent scope nesting and support insertion/removal when entering or leaving scopes.

• When it is used: during semantic analysis for type checking and scope resolution, and later during intermediate-code generation and code generation to determine addresses, types, and calling conventions.

• How it differs from related structures: an abstract syntax tree represents program structure (syntax), a semantic stack holds temporary values during parsing or semantic actions, and a parse table guides parser decisions. None of those serve as the persistent repository of identifier attributes like the symbol table does.

Key takeaway: use the symbol table to look up and record identifier attributes across compiler phases; other structures serve different, complementary roles.