char *str1 = "Hello; /* Statement S1 */
char *str2 = "Hello;"; /* Statement S2 */
int *str3 = "Hello"; /* Statement S3 */
Which of the following options is/are correct?
The given question involves understanding errors in C statements. Let's analyze each statement one by one:
- Statement S1:
char *str1 = "Hello;
This line is intended to assign a string to the pointerstr1. However, the string is not terminated with a closing double quote. This causes a lexical error, as the lexer (lexical analyzer) will not be able to find an end to the string literal. - Statement S2:
char *str2 = "Hello;";
This is a correctly written statement. It assigns the string"Hello;"to the character pointerstr2. The semicolon inside the string is part of the string itself, and the statement ends properly with a semicolon outside the string. There are no lexical or syntactic errors here. - Statement S3:
int *str3 = "Hello";
This line attempts to assign a string to an integer pointer. While syntactically correct, it does not make semantic sense, leading to a semantic error. A string should be assigned to a character pointer, not an integer pointer, as the data types are incompatible.
Now, evaluating the options, the correct answer is:
- S1 has a lexical error and S3 has a semantic error.
This matches our analysis: S1 is missing a closing quote, causing a lexical error, and S3 has a semantic type mismatch.
Other options are incorrect based on the analysis above. S2 does not have any errors.
Important Questions from Lexical Analysis
What is the output of a lexical analyzer?
Which of the following are applications of symbol table ?
(A) Storage allocation
(B) Checking type compatability
(C) Suppressing duplicate error messages
Choose the correct answer from the options given below:
Arrange the given compilation process in the correct order.
a. Linking
b. Assembling
c. Compiling
d. Pre-processing
Which ONE of the following statements is FALSE regarding the symbol table?
- A lexical analyzer uses the following token definitions
- $letter \rightarrow [A-Z a-z]$
- $digit \rightarrow [0-9]$
- $id \rightarrow letter(letter \mid digit)^*$
- $number \rightarrow digit^+$
- $ws \rightarrow (blank \mid tab \mid newline)^+$
For the string given below,
$x1 \quad 23mm \quad 78 \quad y \quad 7z \quad zz5 \quad 14A \quad 8H \quad AaYcD$
the number of tokens (excluding $ws$) that will be produced by the lexical analyzer is __________. (answer in integer)
