cplusplus

The Preliminary of Visual Programming under Linux - Unbelievable - Be more nonchalant when encountering events, and be a bit vague in dealing with the world... sink

2009-9-22 17:35

First of all, I admit that I don't really know the significance of messing around with visual programming under Linux. It's purely driven by interest and curio......

A C course design written under Linux - Inconceivable - Wear other people's shoes, walk your own path, let them look for it... sink

2009-9-22 17:34

Here is the translation of your text into English: --- This is mainly a course design that I borrowed from online resources. It's really well-written, especi......

In C++, `#ifndef`, `#define`, and `#endif` (5) These are preprocessor directives used to prevent multiple inclusions of the same header file, which is often referred to as "include guards." 1. **#ifndef**: This directive checks if a particular identifier (usually a macro) has not been defined yet. 2. **#define**: If the identifier has not been defined, this directive defines it. 3. **#endif**: This directive marks the end of the conditional compilation block started by #ifndef. Here’s an example: ```cpp #ifndef MYHEADER_H // If MYHEADER_H is not defined #define MYHEADER_H // Define MYHEADER_H // Code or declarations go here #endif // End of the conditional compilation block ``` The number "(5)" in your question might refer to a specific context, such as an example number or section, but without additional details, it can be interpreted as part of the labeling or enumeration of examples or sections related to these directives.

2009-9-22 17:32

Although I have always known the functions of these three things: The **#ifndef** in the header file is a very important mechanism. For example, if you have t......