In VS_ In 2019, scanf and other functions are used to prompt the error of unsafe functions

stay VS_2019 Use in scanf Wait for the function to prompt the problem of unsafe function error

• stay VS Call in scanf、sprintf、strcpy、strcat When waiting for a function, you will often be prompted that the function is unsafe , It is recommended to use _s Safer function warnings
• as a result of Visual studio C++ Not really C++, But through Microsoft Company optimized
• Maybe those development engineers at Microsoft think these C There is no boundary check for memory inside the function , It is very likely to cause problems such as memory out of bounds , So an unsafe warning is set

Method 1 , Add a line of declaration at the beginning of the code

 For shielding scanf()  Error of equal function , Add the following code to the code , Put it on the top of the file ！

#define _CRT_SECURE_NO_WARNINGS

Method 2 , Modify the properties of the file

• stay vs in , Right click to select the project name -> attribute -> C/C++ -> The preprocessor -> Preprocessor definition -> Add... To edit _CRT_SECURE_NO_WARNINGS This predefined .