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header-guard [May 14, 2026 at 12:55] – yanevskivheader-guard [May 14, 2026 at 13:01] (current) – yanevskiv
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 # Header guard # Header guard
-**Header guards** are a pattern used in C and C++ programming languages when writing header files. Header files (.h files) are files that are included in source files (.c and .cpp files) using the `#include <...>` directive. +**Header guards** are a pattern used in C and C++ programming languages when writing header files. Header files (.h files) are files that are included in source files (.c and .cpp files) near the top (hence the name) using the `#include <...>` directive. They are used to allow multiple inclusions of the same file but prevent multiple definition errors.  
 + 
 +Header guards follow the same general pattern: 
 +```c 
 +#ifndef __HEADER_GUARD_H__ 
 +#define __HEADER_GUARD_H__ 
 + 
 +// ... 
 + 
 +#endif /* __HEADER_GUARD_H__ (This is just a comment) */ 
 +```
  
 In C and C++ programming languages, `#include` is nothing but text substitution. If you include something multiple times In C and C++ programming languages, `#include` is nothing but text substitution. If you include something multiple times
  
 ## Example ## Example
-A prototypical example of a header guard is the following+A prototypical example of a header guard is the following.
 ```c ```c
 // hello_world.h // hello_world.h
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 ``` ```
  
-### Why?+This allows multiple inclusion of "hello\_world.h"
 ```c ```c
 // main.c // main.c
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 } }
 ``` ```
 +
header-guard.1778763335.txt.gz · Last modified: by yanevskiv