In some programming languages, an identifier is permitted to be a letter followed by any number of letters or digits. If L and D denotes the set of letters and digit respectively. Which of the following expression defines an identifier?

Related MCQs

• Which of the following statements are TRUE? I. There exist parsing algorithms for some programming languages whose complexities are less than O(n3). II. A programming language which allows recursion can be implemented with static storage allocation. III. No L-attributed definition can be evaluated in the framework of bottom-up parsing. IV. Code improving transformations can be performed at both source language and intermediate code level.
• Consider the following expression grammar. The seman-tic rules for expression calculation are stated next to each grammar production. E → number E.val = number. val | E '+' E E(1).val = E(2).val + E(3).val | E '×' E E(1).val = E(2).val × E(3).val The above grammar and the semantic rules are fed to a yacc tool (which is an LALR (1) parser generator) for parsing and evaluating arithmetic expressions. Which one of the following is true about the action of yacc for the given grammar?
• Let L={w \in (0 + 1)*|w has even number of 1s}, i.e. L is the set of all bit strings with even number of 1s. Which one of the regular expression below represents L?
• Which one of the following languages over the alphabet {0,1} is described by the regular expression: (0+1)*0(0+1)*0(0+1)*?
• If s is a string over (0 + 1)* then let n0 (s) denote the number of 0’s in s and n1 (s)the number of l’s in s. Which one of the following languages is not regular?
• Consider the grammar S → (S) | a Let the number of states in SLR(1), LR(1) and LALR(1) parsers for the grammar be n1, n2 and n3 respectively. The following relationship holds good
• Consider the following context free languages: L1 = {0^i 1^j 2^k | i+j = k} L2 = {0^i 1^j 2^k | i = j or j = k} L3 = {0^i 1^j | i = 2j+1} Which of the following option is true?
• Let w be any string of length n is {0,1}*. Let L be the set of all substrings of w. What is the minimum number of states in a non-deterministic finite automaton that accepts L?
• A minimum state deterministic finite automation accepting the language L = {W |W € {0,1}* , number of 0's and 1's in W are divisible by 3 and 5 respectively has
• Consider the languages: L1 ={a^n b^n c^m | n,m >01 and L2 ={a^n b^m c^m |n,m> o) Which one of the following statements is FALSE?