How many tokens are in the C code fragment: int x = a + b * 5;?
The 9 tokens are: 1. int (keyword), 2. x (identifier), 3. = (assignment operator), 4. a (identifier), 5. + (operator), 6. b (identifier), 7. * (operator), 8. 5 (constant), 9. ; (delimiter).
Which phase of a compiler reads source code character-by-character and groups them into meaningful sequences called lexemes?
Lexical analysis (scanning) is the first phase of a compiler that reads raw character streams and converts them into tokens/lexemes.
Which formal language model is used by lexical analyzer generators like LEX/FLEX to recognize tokens?
Lexical rules are specified using regular expressions and recognized efficiently in linear time using Deterministic Finite Automata (DFA).
How many tokens are present in the code fragment for(i=0; i<10; i++)?
The 13 tokens are: 1.for, 2.(, 3.i, 4.=, 5.0, 6.;, 7.i, 8.<, 9.10, 10.;, 11.i, 12.++, 13.).
What token matching rule does a lexical analyzer use when both if and if_var can match the input if_var?
Lexical analyzers use the Longest Match Rule (Maximal Munch) to choose the longest prefix of input that matches any pattern (matching if_var as an identifier rather than keyword if).