Shulou(Shulou.com)06/02 Report--

Editor to share with you what commonly used C++ tips are, I believe most people do not know much about it, so share this article for your reference, I hope you will learn a lot after reading this article, let's go to know it!

1. Is the header file referenced or?

There are still programmers in the code that are still used instead of libraries. Actually, there is a difference between the two libraries:

First of all, it is clearly not recommended to use .h as the standard header file.

Second, in terms of functionality, it includes the IO class and supports both narrow and wide characters, while only char-oriented streams are supported.

Thirdly, the iostream interface standard of C++ has been adjusted. There are differences in the interface and implementation of.

Finally, the component is declared in the std namespace, and the component is global. There are certain risks in the mixed use of the two. You need to be careful.

2. Comma division expression

A comma expression may contain one or more subexpressions separated by commas, for example:

If (+ + x,-- y, cin.good ())

In the above if expression, each statement is executed, but the condition of the entire if is actually the conditional value of the third expression value of if. The default value of cin.good () is 1, which becomes 0 only if the input value is inconsistent with the defined variable type.

The same is true in loop statements. Such as:

While (+ + I,-- j) {;}

The entire while loop stops only when jig0.

3. Run the code before the main function

The unobstructed global object is constructed before the program starts, and this function also returns before main () starts.

Such as:

Class Logger {public: Logger () {activate_log ();} void activate_log () {cout

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