Which of the following is not a valid C keyword?
a) int
b) float
c) for
d) main
Answer:
d) main
Explanation:
In C, int, float, and for are valid keywords with specific meanings, while main is not a keyword but rather a special function name. The main function is the entry point of a C program, where execution begins, but it is not reserved as a keyword. Keywords like int and for are reserved words that cannot be used as identifiers (variable names, function names, etc.) in your program.
Understanding the distinction between keywords and special identifiers like main is essential for writing correct and functional C programs.