a Give an example of a preprocessor directive b Explain what

a) Give an example of a preprocessor directive.

b) Explain what the program counter (PC) is used for in the CPU of a computer.

Solution

a) For many programming languages there are different preprocessor directives the preprocessor directives that are invoked by the compiler to process some programs before compilation.

Let us consider C# programming language preprocessor directives:

-> #define and #undef: These are used to define and undefine conditional compilation symbols

-> #if, #elif, #else, and #endif: These are used to skip part of source code based on conditions.

-> #line: These are used to control line numbers generated for errors and warning.

b) The program counter which is generally called as instruction address register which is used for a preprocessor register that indicates where a computer is in it\'s progarmming sequence The program counter generally contains the address (location) of the instruction being executed at the current time.