Question

Which of the following is not a keyword in C ?

• A. do
• B. break
• C. join
• D. for

Hint:

Common C keywords to remember: if, else, while, do, for, break, continue, return, int, float, char, struct. If it's used in SQL but not C logic, it's probably not a C keyword!

Answer 1

The Correct Option is C

Concept:
• Keywords are reserved words in a programming language that have a predefined meaning to the compiler.
• They cannot be used as identifiers (variable names, function names, etc.).
• ANSI C has 32 reserved keywords.

Step 1: Evaluate common C control flow keywords

• do (Option A): Used in the "do-while" loop construct. It is a keyword.
• break (Option B): Used to exit from a loop or switch statement prematurely. It is a keyword.
• for (Option D): Used for implementing the "for" loop. It is a keyword.

Step 2: Evaluate the word "join"
The word "join" is common in database languages (SQL) or in multithreading libraries (like POSIX threads pthread_join). However, it is not a reserved keyword in the C programming language itself. You are free to use "join" as a variable name or function name in a C program.

Step 3: Reference full keyword list
Standard C keywords include: auto, break, case, char, const, continue, default, do, double, else, enum, extern, float, for, goto, if, int, long, register, return, short, signed, sizeof, static, struct, switch, typedef, union, unsigned, void, volatile, while. "join" is absent from this list.