Every C program needs a main function — that is where the C runtime hands control to your code. But what if you want to write a program without typing main in the source? The answer is a preprocessor macro: #define maps any identifier you choose to main before compilation, so the compiler and linker …
Exercise 7-9. Functions like isupper can be implemented to save space or to save time. Explore both possibilities. Standard library character-classification functions like isupper are typically implemented as macros. There are two design axes: Save time: use a precomputed lookup table — one array access, no branches, O(1) at maximum cache efficiency Save space: use …
Exercise 4-14. Define a macro swap(t,x,y) that interchanges two arguments of type t. (Block structure will help.) A three-argument swap macro: t is the type, x and y are the variables to swap. The block { … } creates a local scope for the temporary, preventing name leakage. The conventional temp variable name _swap_tmp (with …
Write C Program to find sum and product using macros.Macro is a piece of text that is expanded by the preprocessor part of the compiler. This is used in to expand text before compiling. Macro definitions (#define), and conditional inclusion (#if). In many C implementations, it is a separate program invoked by the compiler as …
C Program to demonstrate macros. Macro is a piece of text that is expanded by the preprocessor part of the compiler. This is used in to expand text before compiling. Macro definitions (#define), and conditional inclusion (#if). In many C implementations, it is a separate program invoked by the compiler as the first part of …