First of all, I recommend a github for learning C language/C++, sharing C language/C introduction, learning route, e-book recommendation and download, video recommendation, small projects, dry articles, written test interviews, C language/C++ specifications, open source projects, etc. .
Address: C language/C++ learning platform
| //register keyword requests the compiler to put the variable a directly in the register, which is fast //The variable modified by register cannot take the address in the c language, but the content is done in c++ /* //1 Changes to the register keyword The register keyword asks the "compiler" to store local variables in registers Cannot get register variable address in C language The register keyword is still supported in C++ The C++ compiler has its own optimization methods, and it is possible to optimize without using register The address of register variable can be obtained in C++ //2 When the C++ compiler finds that the address of the register variable needs to be taken in the program, the declaration of the register variable becomes invalid. //3 Early C compilers did not optimize the code, so register variables are a good addition. */ |
| int main22() { register int a = 0; printf("&a = %x\n", &a); system("pause"); return 0; } |