Which data structure is shared across all compiler phases to store information about variable names, types, scopes, and memory locations?
The Symbol Table stores essential metadata about identifiers (type, size, scope, offset) and is accessed and modified across all compiler phases.
Which task is NOT normally performed by a lexical analyzer?
Parenthesis matching is a syntactic property handled by the parser. A lexical analyzer normally recognizes tokens, skips comments/white space, and reports lexical errors such as illegal characters.
What is the time complexity of scanning an n-character input string using a DFA constructed from regular expressions?
Once a DFA is built, processing each character takes O(1) state transitions, making token recognition strictly O(n) for an n-character input.
How many tokens are in the C code string char *s = "Hello, World!";?
Tokens: 1.char, 2.*, 3.s, 4.=, 5."Hello, World!" (string literal counts as 1 token), 6.;.
In compiler construction, what is a lexeme?
A lexeme is the concrete instance of characters in source code (e.g. 123, count) that matches the abstract pattern of a token (e.g. NUMBER, IDENTIFIER).